Engineering Commons^™

Modeling Decision Making In Trauma Centers From The Standpoint Of Complex Adaptive Systems, Castanon De Policarpo

Dissertations

This research examines complex clinical decision-making processes in trauma center units of hospitals in terms of the impact of complexity on the medical team involved in the trauma event. The science of complex adaptive systems together with human judgment theories provide important concepts and tools for responding to health care challenges in this century and beyond. Clinical decision-makers in trauma centers are placed in urgent and anxious situations that are increasingly complex, making decision-making and problem-solving processes multifaceted. Under stressful circumstances, physicians must derive their decision-making schemas (―internal models‖ or ―mental models‖) without the benefits of judicious identification, evaluation, and/or …

Assessment Of Neck And Shoulder Muscle Coactivations And The Effect On The Musculoskeletal System, Regina Derria Pope-Ford

Dissertations

Musculoskeletal disorders (MSDs) constitute one of the most important occupational health issues in healthcare workers who are susceptible to upper extremity disorders. Yet MSDs in the healthcare professions have not been studied extensively beyond the lower back. The focus population for this research is the field of dentistry where neck and shoulder disorders have been documented to have a high prevalence. Though quantitative data has been collected, many prior studies have focused on self-reported information. The goal of this research is to provide insight into the inter-relationship of muscles in the upper extremities. One way to accomplish this is to …

Design And Implementation Of A 16-Bit Flexible Rom-Less Direct Digital Synthesizer In Fpga And Cmos 90nm Technology, Sunny Raj Dommaraju

Browse all Theses and Dissertations

A ROM-less direct digital synthesizer architecture is presented in this thesis. This architecture eliminates the ROM-based phase to sine wave amplitude converter, which is a bottleneck for pushing clock frequencies into the gigahertz range. The design consists of a 16-bit phase accumulator, a set of 18 band pass finite impulse response filters, a 12-bit digital to analog converter and a low pass filter to produce a sine wave with output frequencies ranging from 36 MHz to 72 MHz with a resolution of 3.05 kHz and a 55 dB spur free dynamic range. The same hardware can be used to achieve …

Fatigue Characterization Of Fire Resistant Syntactic Foam Core Material, Mohammad Mynul Hossain

Dissertations

Eco-Core is a fire resistant material for sandwich structural application; it was developed at NC A&T State University. The Eco-Core is made of very small volume of phenolic resin and large volume of flyash by a syntactic process. The process development, static mechanical and fracture, fire and toxicity safety and water absorption properties and the design of sandwich structural panels with Eco-Core was established and published in the literature. One of the important properties is needed for application in transportation vehicles is the fatigue performance under different stress states. Fatigue data are not available even for general syntactic foams. The …

Quantitative Analyses Of Acceptable Noise Level For Air Conduction Listening, Bankole K. Fasanya

Dissertations

This study was conducted to develop quantitative models for Acceptable Noise Level (ANL) under air conduction (AC) listening conditions. Experimental results on the effects of frequency bandwidths on ANL under two listening conditions involving earphones and loudspeaker (sound field) with high and low frequencies and babble noise and white noise revealed: (a) there are statistically significant interactions among the background noise types, the background noise frequency bandwidths and signal source; (b) background noise and noise frequency bandwidths have effects on listener discriminability bias toward the noise and the signal intensity; (c) different listening conditions had different ANL thresholds; and (d) …

Monolithically Integrated Non-Reciprocal Devices Based On Magnetic Thin Films, Gregory Hartman

Browse all Theses and Dissertations

For years technology developers have been reassessing current technology for ways to cut size and cost while maintaining or improving performance. One particular area that continues to grow in importance, yet remains difficult to reassess, are nonreciprocal devices. Components such as isolators and circulators are typically constructed using ferrite materials and permanent magnets; unfortunately, due to size and material properties, those materials are poor choices when attempting to scale down.

The following experiments investigate the ferromagnetic material NiFe and various patterning methods as potential solutions to the scaling and cost questions driven by modern technology requirements. NiFe is of interest …

An Augmented Interaction Strategy For Designing Human-Machine Interfaces For Hydraulic Excavators, Joseph Akyeampong

Dissertations

Lack of adequate information feedback and work visibility, and fatigue due to repetition have been identified as the major usability gaps in the human-machine interface (HMI) design of modern hydraulic excavators that subject operators to undue mental and physical workload, resulting in poor performance. To address these gaps, this work proposed an innovative interaction strategy, termed “augmented interaction”, for enhancing the usability of the hydraulic excavator. Augmented interaction involves the embodiment of heads-up display and coordinated control schemes into an efficient, effective and safe HMI. Augmented interaction was demonstrated using a framework consisting of three phases: Design, Implementation/Visualization, and Evaluation …

Fitness Proportionate Niching: Harnessing The Power Of Evolutionary Algorithms For Evolving Cooperative Populations And Dynamic Clustering, Abrham Tibebu Workineh

Dissertations

Evolutionary algorithms work on the notion of "best fit will survive" criteria. This makes evolving a cooperative and diverse population in a competing environment via evolutionary algorithms a challenging task. Analogies to species interactions in natural ecological systems have been used to develop methods for maintaining diversity in a population. One such area that mimics species interactions in natural systems is the use of niching. Niching methods extend the application of EAs to areas that seeks to embrace multiple solutions to a given problem. The conventional fitness sharing technique has limitations when the multimodal fitness landscape has unequal peaks. Higher …

Tropical Cyclone Intensity Estimation Using Temporal And Spatial Features From Satellite Data, Gholamreza Fetanat Haghighi

Dissertations

Accurate intensity estimation of tropical cyclones (TC) is an important topic of research due to its economic impact and public safety concerns. An accurate measure of the current wind strength is necessary to accurately predict TC intensity. We have developed and tested automated method to estimate TC intensity based on the existing historical satellite images alone. The Hurricane Satellite data (HURSAT-B1) is used to develop the algorithm, which focuses on the North Atlantic from 1978-2009. The algorithm is trained and validated using aircraft reconnaissance-based data. Here, the data is restricted to include only fixes that are over water and are …

A Novel Approach To Intelligent Navigation Of A Mobile Robot In A Dynamic And Cluttered Indoor Environment, Daniel Opoku

Dissertations

The need and rationale for improved solutions to indoor robot navigation is increasingly driven by the influx of domestic and industrial mobile robots into the market. This research has developed and implemented a novel navigation technique for a mobile robot operating in a cluttered and dynamic indoor environment. It divides the indoor navigation problem into three distinct but interrelated parts, namely, localization, mapping and path planning. The localization part has been addressed using dead-reckoning (odometry). A least squares numerical approach has been used to calibrate the odometer parameters to minimize the effect of systematic errors on the performance, and an …

Computational Material Modeling For Mechanical Properties Prediction And A Methodology For Mie Gruneisen Equation Of State Characterization Via Molecular/Nano Scale Cementitious Material Constituents, Ahmed Mohamed

Dissertations

Cementitious materials have complex hierarchical structures with random features that range from nanometer (nm) to millimeter (mm) scale. Processes occurring at the nanometer scale affect the performance at larger length scales. The present work employs molecular dynamics (MD) simulations as the computational modeling methodology to predict mechanical properties for both hydrated and unhydrated cementitious materials at the molecular/nano scale level. A detailed study on the effect of increasing MD simulation cell size, dynamics time duration on the predicted mechanical properties was performed. Further studies focused on understanding the effect of higher thermodynamic pressure states on predicted …

Design Of Fountain Codes With Error Control, Amrit Kharel

Electronic Theses and Dissertations

This thesis is focused on providing unequal error protection (uep) to two disjoint sources which are communicating to a comdestination via a comrelay by using distributed lt codes over a binary erasure channel (bec), and designing fountain codes with error control property by integrating lt codes with turbo codes over a binary input additive white gaussian noise (bi-awgn) channel. A simple yet efficient technique for decomposing the rsd into two entirely different degree distributions is developed and presented in this thesis. These two distributions are used to encode data symbols at the sources and the encoded symbols from the sources …

Enhanced Pvdf Film For Multi Energy Harvesting, Ranmunige Nadeeka Karunarathna

Electronic Theses and Dissertations

No abstract provided.

Autonomous Recovery Of Reconfigurable Logic Devices Using Priority Escalation Of Slack, Naveed Imran

Electronic Theses and Dissertations

Field Programmable Gate Array (FPGA) devices offer a suitable platform for survivable hardware architectures in mission-critical systems. In this dissertation, active dynamic redundancy-based fault-handling techniques are proposed which exploit the dynamic partial reconfiguration capability of SRAM-based FPGAs. Self-adaptation is realized by employing reconfiguration in detection, diagnosis, and recovery phases. To extend these concepts to semiconductor aging and process variation in the deep submicron era, resilient adaptable processing systems are sought to maintain quality and throughput requirements despite the vulnerabilities of the underlying computational devices. A new approach to autonomous fault-handling which addresses these goals is developed using only a uniplex …

A Dynamic Enrollment Simulation Model For Planning And Decision-Making In A University, Luis Robledo

Electronic Theses and Dissertations

Decision support systems for university management have had limited improvement in the incorporation of new cutting-edge techniques. Most decisionmakers use traditional forecasting methods to base their decisions in order to maintain financially affordable programs and keep universities competitive for the last few decades. Strategic planning for universities has always been related to enrollment revenues, and operational expenses. Enrollment models in use today are able to represent forecasting based on historical data, considering usual variables like student headcount, student credit, among others. No consideration is given to students’ preferences. Retention models, associated to enrollment, deal with average retention times leaving off …

Sustainability Analysis Of Intelligent Transportation Systems, Tolga Ercan

Electronic Theses and Dissertations

Commuters in urban areas suffer from traffic congestion on a daily basis. The increasing number of vehicles and vehicle miles traveled (VMT) are exacerbating this congested roadway problem for society. Although literature contains numerous studies that strive to propose solutions to this congestion problem, the problem is still prevalent today. Traffic congestion problem affects society’s quality of life socially, economically, and environmentally. In order to alleviate the unsustainable impacts of the congested roadway problem, Intelligent Transportation Systems (ITS) has been utilized to improve sustainable transportation systems in the world. The purpose of this thesis is to analyze the sustainable impacts …

Differential Games For Multi-Agent Systems Under Distributed Information, Wei Lin

Electronic Theses and Dissertations

In this dissertation, we consider differential games for multi-agent systems under distributed information where every agent is only able to acquire information about the others according to a directed information graph of local communication/sensor networks. Such games arise naturally from many applications including mobile robot coordination, power system optimization, multiplayer pursuit-evasion games, etc. Since the admissible strategy of each agent has to conform to the information graph constraint, the conventional game strategy design approaches based upon Riccati equation(s) are not applicable because all the agents are required to have the information of the entire system. Accordingly, the game strategy design …

Growth And Characterization Of Zno Based Semiconductor Materials And Devices, Ming Wei

Electronic Theses and Dissertations

Wide band gap semiconductors such as MgxZn1-xO represent an excellent choice for making optical photodetectors and emitters operating in the UV spectral region. High crystal and optical quality MgxZn1-xO thin films were grown epitaxially on c-plane sapphire substrates by plasma-assisted Molecular Beam Epitaxy. ZnO thin films with high crystalline quality, low defect and dislocation densities, and sub-nanometer surface roughness were achieved by applying a low temperature nucleation layer. The critical growth conditions were discussed to obtain a high quality film: the sequence of Zn and O sources for initial growth of nucleation layer, growth temperatures for both ZnO nucleation and …

Path Clearance For Emergency Vehicles Through The Use Of Vehicle-To-Vehicle Communication, Craig Jordan, Mecit Cetin, R. Michael Robinson

VMASC Publications

The study described in this paper evaluated and tested a new strategy to enable emergency response vehicles (EVs) to navigate through congestion at signalized intersections more efficiently. The proposed strategy involves the use of vehicle-to-vehicle communication to send messages to alert vehicles to the approach of the EV and to provide specific instructions on maneuvering to allow the EV to proceed through congested signalized intersections as quickly as possible. This movement is achieved by creation of a split in the vehicle queue in one lane at a critical location to allow the EV to proceed at its desired speed but …

Managing, Controlling And Improving The Treatment Of Produced Water Using The Six Sigma Methodology For The Iraqi Oil Fields, Maher T. Al-Shamkhani

Electronic Theses and Dissertations

Produced Water (PW) is the largest volume of waste that is normally generated during oil and gas production. It has large amounts of contaminants that can cause negative environmental and economic impacts. The management method for PW relies highly on types and concentrations of these contaminants, which are field dependent and can vary from one oil field to another. Produced water can be converted to fresh water if these contaminants are removed or reduced to the acceptable drinking water quality level. In addition, increasing oil production rate and reducing amounts of discharged harmful contaminants can be achieved by removing dissolved …

Real-Time In Vivo Imaging Of Size-Dependent Transport And Toxicity Of Gold Nanoparticles In Zebrafish Embryos Using Single Nanoparticle Plasmonic Spectroscopy, Lauren M. Browning, Tao Huang, Xiao-Hong Nancy Xu

Chemistry & Biochemistry Faculty Publications

Noble metal nanoparticles (NPs) show distinctive plasmonic optical properties and superior photostability, enabling them to serve as photostable multicoloured optical molecular probes and sensors for real-time in vivo imaging. To effectively study biological functions in vivo, it is essential that the NP probes are biocompatible and can be delivered into living organisms non-invasively. In this study, we have synthesized, purified and characterized stable (non-aggregated) gold (Au) NPs (86.2 +/- 10.8 nm). We have developed dark-field single NP plasmonic microscopy and spectroscopy to study their transport into early developing zebrafish embryos (cleavage stage) and their effects on embryonic development …

Bioremediation Of Chlorinated Ethanes And Ethenes In Vertical Flow Engineered Wetland Systems, Christopher Akudo

LSU Doctoral Dissertations

Sustainable treatment of chlorinated ethanes and ethenes contaminated groundwater using vertical flow engineered wetland systems were investigated in microcosm and column studies. Experiments on environmental and biogeochemical factors that affect system performance were conducted, and a numerical model involving advection, sorption, and sequential biodegradation was developed to describe the fate and transport of the contaminants of concern in the treatment wetland bed. 1,1-dichloroethane (1,1-DCA) and cis-1,2-dichloroethene (cis-1,2-DCE) were used as the chemicals of interest. The presence of cis-1,2-DCE inhibited dechlorination of 1,1-DCA but cis-1,2-DCE dechlorination was not affected by the presence of 1,1-DCA. Simulation runs showed that the treatment bed …

Nanoindentation Characterization Of Clay Minerals And Clay-Based Hybrid Bio-Geomaterials, Rohit Raj Pant

LSU Doctoral Dissertations

Layered hydrous aluminosilicates are key constituent minerals in rocks, soils, and other parts of the Earth crust. Understanding mechanical properties of these aluminosilicates is crucial for seismic study, stability of parent rocks and geomaterials, and for geophysical subsurface exploration. Recently, growing prospects of clay based nanocomposites have renewed further interest in understanding the fundamental elastic and plastic properties of hydrous aluminosilicates. Their distinct, nanoscale layered crystal structure is known to result in anisotropic responses to loading, however, owing to their tiny sizes; it is a significant challenge to determine the anisotropic properties. There is a little data available in the …

Induction Motors With Rotor Helical Motion, Ebrahim Amiri

LSU Doctoral Dissertations

Performance analysis of the twin-armature rotary-linear induction motor, a type of motor with two degrees of mechanical freedom, is the subject of this dissertation. The stator consists of a rotary armature and linear armature placed aside one another. Both armatures have a common rotor which can be either solid or cage rotor. The rotor can move rotary, linearly or with helical motion. The linear motion generates dynamic end effect on both linear and rotary armature. Modeling such an effect in rotary armature is a significant challenge as it requires a solution considering motion with two degrees of mechanical freedom. In …

The Investigation Of Valve Operators' Torque Production Capabilities And Optimal Handwheel Height, Angle, And Opening Technique, Saif K. Al-Qaisi

LSU Doctoral Dissertations

This research consists of two projects concerned with handwheel-valve operations. The objectives of poject-1 were to: (1) introduce an ergonomically-modified valve-wrench and compare it to conventional valve-opening methods, in terms of efficiency (time to open valve), perceived physical exertion (Borg-scale), and muscle loading of shoulder and trunk muscles; and (2) determine whether the torque setting (15 Nm and 30 Nm) of the valve affects the preferred valve-opening method. Four methods were evaluated, including using bare hands (BH), conventional wrench-restricted (CW-R, assumes presence of obstructions), conventional wrench-unrestricted (CW-U, assumes no obstructions), and modified wrench (MW). Electromyography (EMG) activities were measured from …

Molecular Dynamics Of Ionic Liquids In Nanoporous Electrodes, Nav Nidhi Rajput

LSU Doctoral Dissertations

Molecular dynamics simulations were performed to investigate structural, dynamical and electrical properties of ionic liquids (ILs) confined inside different nanoporous materials. These systems have potential uses in environmental and energy applications. The main goal is to understand how these IL properties are affected by a) characteristics of nanoporous materials such as chemical nature of the pore walls (e.g., carbon, titania), pore size and pore morphology, and b) characteristics of electrolyte, such as amount of IL inside the pores (pore loading) and concentration of organic solvent, in the case of mixtures of ILs with organic solvents. The results obtained in this …

Optimal Consignment Stocking Policies For A Supply Chain Under Different System Constraints, Hui Zhi Yi

LSU Doctoral Dissertations

The research aims are to enable the decision maker of an integrated vendor-buyer system under Consignment Stock (CS) policy to make the optimal/sub-optimal production/replenishment decisions when some general and realistic critical factors are considered. In the system, the vendor produces one product at a finite rate and ships the outputs by a number of equal-sized lots within a production cycle. Under a long-term CS agreement, the vendor maintains a certain inventory level at the buyer’s warehouse, and the buyer compensates the vendor only for the consumed products. The holding cost consists of a storage component and a financial component. Moreover, …

Emergence Of Delamination Fractures Around Casing And Its Stability, Wei Wang

LSU Doctoral Dissertations

The cement sheath failures and nearby wellbore failures may lead to upward flow of drilling fluid or formation fluid, which may have significantly adverse consequences like loss of reserve and environmental hazards. In order to maintain wellbore integrity in the long term, it is expedient to examine the causes of failures around the wellbore and propose suitable numerical models to predict annulus cracks around the casing. The complex failure behavior of cement/rock interfaces observed in the laboratory experiments does not look like the behavior of linear or simple nonlinear mechanical interfaces. Cohesive zone method (CZM) with BK-form bilinear traction separation …

Assessing Levels Of Reliability For Design Criteria For Hurricane And Storm Damage Risk Reduction Structures, Christopher Leslie Dunn

LSU Doctoral Dissertations

In the wake of Hurricane Katrina, the U.S. Army Corps of Engineers (USACE) updated design methodologies and required factors of safety for hurricane and storm damage risk reduction system (HSDRRS) structures to incorporate lessons-learned from the system performance during Katrina and results of state-of-the-art research in storm surge modeling and foundation behavior. However, the criteria (USACE 2008) were not calibrated to a target reliability, which creates the need to understand the reliability provided by designs using those criteria, especially for pile-founded structures subject to global instability. This dissertation presents a methodology for quantifying the reliability of pile-founded structures that can …

A Study On The Cleaning And Modification Of Metal Surfaces By Direct Current Cathodic Electrolytic Plasma Process, Jiandong Liang

LSU Doctoral Dissertations

The processes of surface treatments or surface modifications, more formally known as surface engineering, tailor the surfaces of engineering materials. The treatments are usually intended to change physical properties such as thermal or electrical conductivity, modify the surface dimensions, i.e. roughness, etc. A novel surface treatment method, Electrolytic Plasma Process (EPP), was developed for coating purposes, in its early developmental stage. In this work, the major effort is to avoid using any environmental hazardous chemical (coatings) and to extend such its application to some new fields. The general response of the substrate material under electrolytic plasma process was summarized including …