Engineering Commons^™

Ultra Wideband Pulse Shaping, Pawel Rulikowski

Theses

Methods for shaping of sophisticated, transient, ultra wideband (UWB) waveforms and pulses are presented. The methods include novel circuits based on step recovery diodes (SRDs) and quasi-transversal filter concepts but the majority of the work focuses on UWB pulse shaping using completely passive nonuniform transmission lines (NUTLs). It is shown, for the first time, that NUTLs can be used to generate highly sophisticated arbitrary UWB pulse shapes, including modified Hermite polynomial (MHP) and approximate spheroidal wave function (APSWF) pulses which are not known to have been previously generated in practice, and a generalized methodology, verified by experiments, for design of …

Rubble-Mound Structure Design In The Coastal Environment, Jack Murphy

Theses

The main aims of this thesis were to investigate the main aspects of the design and implementation of rubble-mound structures as a form of shoreline stabilisation and coastal defence. An emphasis has been placed on the Irish context of how these structures have been implemented in the past. The intention was that this work would improve the understanding of the use of these structures for future projects both in Ireland and internationally.

This work required a literature review which investigated the general aspects of rubble-mound structures, the coastal environment, and the theory of designing the structures’ layout, cross-section and impact …

Semi-Rigid Steelwork Connections, Conor Murphy

Theses

This thesis sets out to assess the stiffiiess of typical fin plate steelwork connections. The classification of joints as pinned, semi-rigid or fixed is described and the different models of moment-rotation relationship are explained. Eurocode treatment of steelwork connections is assessed with particular emphasis on joint stiffness. Procedures for the design of fin plate connections are set out and an example presented and a spreadsheet developed. Tests on a number of fin plate connections were carried out in the Heavy Structures Laboratory, to determine the moment rotation characteristics. The finite element software LUSAS was used to analyse the fin plate …

Miniature Embedded Module For Prognostic Health Monitoring (Phm) Of Electronic Systems, Liam Moore

Theses

Sensing systems for reliability prognostics are used extensively in life- and mission- critical electronics systems. They allow monitoring of reliability stresses in real time and scheduling of preventative maintenance before system failure. However, reliability prognostics systems are, in general, large and expensive and cannot be used in lower cost, small sized or portable products.

This thesis presents a sensing module for reliability prognostics which is only 1cm in volume and uses only commercial off-the-shelf components. In its 1cm package, the module combines all the necessary elements to act as an embedded prognostic sensor system for multi axial strain, vibration, humidity …

Nano-Materials By Design And Their Applications In Infrastructure, Hunain Said Alkhateb

Electronic Theses and Dissertations

For utilizing nano materials in infrastructure applications, they should exist in huge quantities, in low cost, and they should be applied efficiently to achieve the ultimate goal design, based on fundamental mechanical and physical laws. To achieve this goal multiscale characterization and modeling is needed to deliver our thorough application effectively. The main objective in this research is to implement multiscale characterization of the nano-micro-meso-macro properties of advanced polymeric and cementitious nanocomposites, to correlate mechanical properties to morphology. This include a proposed joint experimental-theoretical approach.

Processing Parameters And Chamber Length Impact On Detached Die And Attached Die Resin Injection Pultrusion, Dinesh Raj Palikhel

Electronic Theses and Dissertations

Injection pultrusion is an efficient and highly automated continuous process for high-quality, low-cost, high-volume manufacturing of composites. The main objective of this study is to analyze "attached die configuration" and "detached die configuration" for the better injection pultrusion process. In this work the impact of various processing parameters on complete wet out of composite parts is investigated in the attached die and detached die injection pultrusion with various chamber length considerations. The various processing parameters considered are pull speed, fiber volume fraction, resin viscosity, injection port location and compression ratio. 3-D finite volume technique is used to simulate the liquid …

Seismic Tomography For The Integrity Assessment Of Earthen Dams And Levees., Leti Teklu Wodajo

Electronic Theses and Dissertations

Dams are a vital part of a nation's infrastructure. Considering the fact that many of the dams in the United States have approached or are approaching their projected life expectancy of 50 years, these critical infrastructures represent a risk to public safety. Minimizing this risk requires an ongoing safety inspection, monitoring, maintenance and rehabilitation program. This research examines the use of a non-invasive geophysical seismic method to provide additional information where the usual visual inspection is insufficient and the comboring investigation is not an option. Even though seismic techniques provide valuable information of the subsurface strata, the interpretation is not …

Advanced Studies On Series Impedance In Waveguides With An Emphasis On Source And Transfer Impedance, Jinghao Liu

University of Kentucky Doctoral Dissertations

Series impedances, including source and transfer impedances, are commonly used to model a variety of noise sources and noise treatment elements in duct systems. Particle velocity is assumed to be constant on the plane where the series impedances are defined. The research reported herein details investigations into measuring source and transfer impedance. Especially, the measurement and prediction of the transfer impedance of micro-perforated panel (MPP) absorbers is considered.

A wave decomposition method for measuring source impedance and source strength was developed that was purely based on acoustic concepts instead of the equivalent circuit analysis. The method developed is a two-load …

Estimation Of Pedestrian Safety At Intersections Using Simulation And Surrogate Safety Measures, Nithin K. Agarwal

University of Kentucky Doctoral Dissertations

With the number of vehicles increasing in the system every day, many statewide policies across the United States aim to increase the use of non- motorized transportation modes. This could have safety implications because the interaction between motorists and non-motorists could increase and potentially increasing pedestrian-vehicle crashes. Few models that predict the number of pedestrian crashes are not sensitive to site-specific conditions or intersection designs that may influence pedestrian crashes. Moreover, traditional statistical modeling techniques rely extensively on the sparsely available pedestrian crash database.

This study focused on overcoming these limitations by developing models that quantify potential interactions between pedestrians …

Three Dimensional Modeling And Animation Of Facial Expressions, Alice J. Lin

University of Kentucky Doctoral Dissertations

Facial expression and animation are important aspects of the 3D environment featuring human characters. These animations are frequently used in many kinds of applications and there have been many efforts to increase the realism. Three aspects are still stimulating active research: the detailed subtle facial expressions, the process of rigging a face, and the transfer of an expression from one person to another. This dissertation focuses on the above three aspects.

A system for freely designing and creating detailed, dynamic, and animated facial expressions is developed. The presented pattern functions produce detailed and animated facial expressions. The system produces realistic …

Modeling Pedestrian Behavior In Video, Paul Scovanner

Electronic Theses and Dissertations

The purpose of this dissertation is to address the problem of predicting pedestrian movement and behavior in and among crowds. Specifically, we will focus on an agent based approach where pedestrians are treated individually and parameters for an energy model are trained by real world video data. These learned pedestrian models are useful in applications such as tracking, simulation, and artificial intelligence. The applications of this method are explored and experimental results show that our trained pedestrian motion model is beneficial for predicting unseen or lost tracks as well as guiding appearance based tracking algorithms. The method we have developed …

Lateral Power Mosfets Hardened Against Single Event Radiation Effects, Patrick Michael Shea

Electronic Theses and Dissertations

The underlying physical mechanisms of destructive single event effects (SEE) from heavy ion radiation have been widely studied in traditional vertical double-diffused power MOSFETs (VDMOS). Recently lateral double-diffused power MOSFETs (LDMOS), which inherently provide lower gate charge than VDMOS, have become an attractive option for MHz-frequency DC-DC converters in terrestrial power electronics applications [1]. There are growing interests in extending the LDMOS concept into radiation-hard space applications. Since the LDMOS has a device structure considerably different from VDMOS, the well studied single event burn-out (SEB) or single event gate rapture (SEGR) response of VDMOS cannot be simply assumed for LDMOS …

Computationally Efficient Digital Backward Propagation For Fiber Nonlinearity Compensation, Likai Zhu

Electronic Theses and Dissertations

The next generation fiber transmission system is limited by fiber nonlinearity. A distributed nonlinearity compensation method, known as Digital Backward Propagation (DBP), is necessary for effective compensation of the joint effect of dispersion and nonlinearity. However, in order for DBP to be accurate, a large number of steps are usually required for long-haul transmission, resulting in a heavy computational load. In real time DBP implementation, the FIR filters can be used for dispersion compensation and account for most of the computation per step. A method of designing a complementary filter pair is proposed. The individual errors in the frequency response …

Design And Optimization Of A Wave Energy Harvester Utilizing A Flywheel Energy Storage System, Steven Alexander Helkin

Electronic Theses and Dissertations

This thesis details the design and optimization of a buoy used to collect renewable energy from ocean waves. The proposed buoy is a point absorber—a device that transforms the kinetic energy of the vertical motion of surface waves into electrical energy. The focus of the research is on the mechanical system used to collect the energy, and methods to improve it for eventual use in an actual wave energy harvester. A flywheel energy storage system was utilized in order to provide an improved power output from the system, even with the intermittent input of force exerted by ocean waves. A …

Evaluation And Modeling Of The Safety Of Open Road Tolling System, Muamer Ali Abuzwidah

Electronic Theses and Dissertations

The goal of this thesis is to examine the traffic safety impact of upgrading Toll Plazas (TP) to Open Road Tolling (ORT). The ORT could enhance safety but could also pose some traffic safety concerns at Toll plazas. Crashes from eight years were investigated by evaluating the crash data before and after the implementation of the ORT. The study was conducted by using two approaches: 1) a simple before and after study and with a comparison group; 2) a modeling effort to help understand the relationship between the crash frequency and several important factors and circumstances such as injury severity, …

Homologous Pairing Through Dna Driven Harmonics-- A Simulation Investigation, Richard J. Calloway

Electronic Theses and Dissertations

The objective of this research is to determine if a better understanding of the “molecule of life”, deoxyribonucleic acid or DNA can be obtained through Molecular Dynamics (MD) modeling and simulation (M&S) using contemporary MD M&S. It is difficult to overstate the significance of the DNA molecule. The now-completed Human Genome Project stands out as the most significant testimony yet to the importance of understanding DNA. The Human Genome Project (HGP) enumerated many areas of application of genomic research including molecular medicine, energy sources, environmental applications, agriculture and livestock breeding to name just a few. (Science, 2008) In addition to …

Fourier Transform Emission Spectroscopy Of Yh And Yd: Observation Of New A¹Δ And B¹Π Electronic States, R. S. Ram, G. Li, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

The emission spectra of YH and YD molecules have been investigated in the 3600–12 000 cm⁻¹ region using a Fourier transform spectrometer. Molecules were formed in an yttrium hollow cathode lamp operated with a continuous flow of a mixture of Ne and Ar gases, and YH and YD were observed together in the same spectra. A group of bands observed near 1 μm have been identified as 0-0 and 1-1 bands of the A¹Δ-X¹Σ⁺ and B¹Π-X¹Σ⁺ transitions of YH and the 0-0 bands of the same two transitions …

Spatio-Temporal Variations In Soil Moisture And Physicochemical Properties Of A Typical Semiarid Sand-Meadow-Desert Landscape As Influenced By Land Use, L. Duan, T. Liu, X. Wang, G. Wang, L. Ma, Y. Luo

Civil & Environmental Engineering Faculty Publications

A good understanding of the interrelations between land cover alteration and changes in hydrologic conditions (e.g., soil moisture) as well as soil physicochemical properties (e.g., fine soil particles and nutrients) is crucial for maintaining the fragile hydrologic and environmental conditions of semiarid land, such as the Horqin Sandy Land in China, but is lacking in existing literature. The objectives of this study were to examine: (1) spatio-temporal variations of soil moisture and physicochemical properties in semiarid land; and (2) how those variations are influenced by land cover alteration. Using the data collected in a 9.71 km2 well-instrumented area of the …

Load-Bearing Capacity Of Footing Resting On Multilayer Reinforced Fly Ash Slope, K S. Gill, A K. Choudhary, J N. Jha, S K. Shukla

Research outputs 2011

In several parts of the world, disposal of waste materials like fly ash is a great problem. Applications of some waste materials as structural fills in foundations is one of the best solutions to disposal problems, because wastes can be used in large volumes. There may be difficulty due to poor load-bearing capacity of fly ash, especially when footings are rested on the top of the fly ash fill slope; but inclusion of polymeric reinforcements as horizontal sheets within the fill may be one of the most viable solutions to improving the load-bearing capacity of reinforced fly ash slope. The …

Theory Of The Scattering Of Light And Surface Plasmon Polaritons By Finite-Size Subwavelength Metallic Defects Via Field Decomposition, Guangyuan Li, Feng Xiao, Lin Cai, Kamal Alameh, Anshi Xu

Research outputs 2011

A theoretical model is presented for the scattering of light and surface plasmon polaritons (SPPs) by finite-size subwavelength metallic defects. Based on the decomposition of the scattered fields into SPPs and quasi-cylindrical waves (CWs), an SPP–CW model is developed to depict the multiple scattering of SPPs and CWs in finite-size defects using the elementary scattering processes in a single one. The involved elementary scattering of the CW, as well as the CW-related coefficients, which are difficult or even impossible to define and calculate according to classical scattering theory, is clarified. A close relationship between the scattering coefficients of the SPP …

Presentation: Proving Sustainability: The International Development Monitoring Initiative, Evan A. Thomas

Mechanical and Materials Engineering Faculty Publications and Presentations

Presentation detailing the activities and products of the Sustainable Water, Energy and Environmental Technologies Laboratory at Portland State University (SWEETLab). The lab also works to develop standards to help evaluate and compare projects and outcomes around the world. Water treatment and sanitation practices, as well as newly designed cookstoves, are highlighted.

The Effect Of Exopolymers On The Compressibility And Shear Strength Of Kaolinite, Rick Alton Nugent

LSU Doctoral Dissertations

Erosion and subsidence threaten coastal infrastructure and natural habitats throughout the coastal United States, and this threat is especially significant along the Louisiana coastline since wetland clays are generally weak and highly compressible. Hydraulic pumping of dredged sediment is a common method for combating damage caused by erosion and subsidence, but the high water content slurry deposited is very compressible with low shear strength. Although conventional soil amendments are effective for reducing compressibility and increasing shear strength, these stabilizers are often caustic or toxic, making them too risky to use. Exopolymers, however, have the potential to improve sediment stability without …

Advanced Linear Identification Techniques For Signal Processing And Digital Video Broadcasting, Xiaoyu Feng

LSU Doctoral Dissertations

Linear identification technique is to linearly embed a piece of unique information into digital media data for the purpose of satisfying specific demands such as identification, annotation, and copyright, etc. We need to consider the quantity and the quality of identification data to be embedded as well as the corresponding interference to the original subject signal. However, there exist no generalized computationally-efficient optimization techniques for linear identification up to now. Therefore, in this dissertation work, we try to theoretically investigate the advanced linear identification techniques and combat the tradeoff problems between the quality of the embedded identification data and the …

Numerical Studies Of Flow In Porous Media Using An Unstructured Approach, Nathan Matthew Lane

LSU Doctoral Dissertations

Flow and transport in porous media is relevant to many areas of engineering and science including groundwater hydrology and the recovery of oil and gas. Porous materials are characterized by the unique shape and connectivity of the internal void structures which give rise to a large range in macroscopic transport properties. Historically an inability to accurately describe the internal pore-structure has prevented detailed study of the role of pore structure on transport. In recent decades however, the combination of high resolution imaging technologies with computational modeling has seen the development of fundamental pore-scale techniques for studying flow in porous media. …

Analytical Design Method For Cold Production Of Heavy Oil With Bottom Water Using Bilateral Sink Wells, Wenting Qin

LSU Doctoral Dissertations

Few heavy oil reservoirs with strong bottom water drives have been developed successfully because of severe water coning. Water coning tends to cause low ultimate recovery, low well productivity, and high water production. Although thermal and gravity-assisted methods might improve recovery in oil reservoirs, such methods are widely perceived as either economically unfavorable or technologically infeasible. This study proposes a new, cold production technique, called Bilateral Water Sink (BWS), to meet those challenges. The BWS method suppresses water cresting by producing oil and water simultaneously from separate, horizontal wells completed in the oil and water zones; the oil and water …

Development Of A Time-Dependent, Audio-Visual, Stated Choice Method Of Data Collection For Hurricane Evacuation Behavior, Ravindra Gudishala

LSU Doctoral Dissertations

Revealed preference is the traditional method to collect hurricane evacuation behavior data. However, revealed preference surveys, as they are currently administered, have the disadvantage that they are unable to collect time-sensitive and policy-sensitive data needed to test evacuation policies. In contrast, data collected from a time-dependent, stated-choice survey will allow researchers to collect not only time-sensitive and policy-sensitive data but also information that will allow testing potential new evacuation policies. However, no research has been conducted to establish the methodology of such a survey. To fill the gap, this study was conducted to develop a new time-dependent, audio-visual, stated-choice method …

Hydraulic Conductivity Of Model Soil-Bentonite Backfills Subjected To Wet-Dry Cycling, Michael A. Malusis, Jeffrey C. Evans, Seungchoel Yeom

Faculty Journal Articles

The potential for changes in hydraulic conductivity, k, of two model soil-bentonite (SB) backfills subjected to wet-dry cycling was investigated. The backfills were prepared with the same base soil (clean, fine sand) but different bentonite contents (2.7 and 5.6 dry wt %). Saturation (S), volume change, and k of consolidated backfill specimens (effective stress = 24 kPa) were evaluated over three to seven cycles in which the matric suction, Y_m, in the drying stage ranged from 50 to 700 kPa. Both backfills exhibited susceptibility to degradation in k caused by wet-dry cycling. Mean values of …

A New Approach To Algebraic Coding Theory Through The Applications Of Soft Sets, Florentin Smarandache, Mumtaz Ali

Branch Mathematics and Statistics Faculty and Staff Publications

Algebraic codes play a signifcant role in the minimisation of data corruption which caused by defects such as inference, noise channel, crosstalk, and packet loss. In this paper, we introduce soft codes (soft linear codes) through the application of soft sets which is an approximated collection of codes. We also discuss several types of soft codes such as type-1 soft codes, complete soft codes etc. Further, we construct the soft generator matrix and soft parity check matrix for the soft linear codes. Moreover, we develop two techniques for the decoding of soft codes.

Uniform And Partially Uniform Redistribution Rules, Florentin Smarandache, Jean Dezert

Branch Mathematics and Statistics Faculty and Staff Publications

This paper introduces two new fusion rules for combining quantitative basic belief assignments. These rules although very simple have not been proposed in literature so far and could serve as useful alternatives because of their low computation cost with respect to the recent advanced Proportional Conflict Redistribution rules developed in the DSmT framework.

Evidence Supporting Measure Of Similarity For Reducing The Complexity In Information Fusion, Florentin Smarandache, Jean Dezert, Xinde Li, Xinhan Huang

Branch Mathematics and Statistics Faculty and Staff Publications

This paper presents a new method for reducing the number of sources of evidence to combine in order to reduce the complexity of the fusion processing. Such a complexity reduction is often required in many applications where the real-time constraint and limited computing resources are of prime importance. The basic idea consists in selecting, among all sources available, only a subset of sources of evidence to combine. The selection is based on an evidence supporting measure of similarity (ESMS) criterion which is an efficient generic tool for outlier sources identification and rejection. The ESMS between two sources of evidence can …