Engineering Commons^™

Relaxation Adaptive Memory Programming For The Resource Constrained Project Scheduling Problem, Robert Christopher-Lee Riley

Electronic Theses and Dissertations

The resource constrained project scheduling problem (RCPSP) is one of the most intractable problems in operations research; it is NP-hard in the strong sense. Due to the hardness of the problem, exact solution methods can only tackle instances of relatively small size. For larger instances commonly found in real applications heuristic solution methods are necessary to find near-optimal solutions within acceptable computation time limits. In this study algorithms based on the relaxation adaptive memory programming (RAMP) method (Rego, 2005) are developed for the purpose of solving the RCPSP. The RAMP algorithms developed here combine mathematical relaxation, including Lagrangian relaxation and …

A Proposed Return Algorithm For Elastoplastic Constitutive Relations, David A. Cooper, David L. Littlefield

Early Career Technical Journal (ECTJ)

Section 5: Numerical Methods; pp. 121-125

Gravitational Stabilization Methods For Hydrocodes, Gerald Pekmezi, David Littlefield, Stephen Akers, Kent Danielson

Early Career Technical Journal (ECTJ)

Section 5: Numerical Methods; pp. 150-157

Geochemical Studies Of Backfill Aggregates, Lake Sediment Cores And The Hueco Bolson Aquifer, Anita Thapalia

Open Access Theses & Dissertations

This Dissertation comprises of three different researches that focuses on the application of geochemistry from aggregates, lake sediment cores and Hueco Bolson Aquifer. Each study is independent and presented in the publication format. The first chapter is already published and the second chapter is in revision phase. Overall, three studies measure the large scale (field) as well as bench scale (lab) water-rock interactions influenced by the climatic and anthropogenic factors spans from the field of environmental geology to civil engineering.

The first chapter of this Dissertation addresses the chemical evaluation of coarse aggregates from six different quarries in Texas. The …

Nanometric Structure-Property Relationship In Hafnium Oxide Thin Films Made By Sputter-Deposition, Mirella Vargas

Open Access Theses & Dissertations

Hafnium oxide (HfO2) is technologically an important material, which exhibits a unique set of properties such as a high dielectric constant (k~25) and wide band gap (~5.7 eV) which make this material attractive in the fields of microelectronics and optoelectronics. HfO2 has become the leading candidate to replace SiO2 dielectrics in gate oxides due to a higher permittivity and reportedly lower electron tunneling effects. HfO2 exhibits various polymorphs; the thermodynamic stability and phase existence depends on the temperature and pressure conditions. In addition, the controlled growth and manipulation of specific HfO2 crystal structures at the nanoscale dimensions is the driving …

Injury Prevention With Physical Therapy, Karen Kott, Margaret F. Lemaster

Rehabilitation Sciences Faculty Publications

(First paragraph) Ergonomics is the study of human performance (positioning and movement) and workplace design, such as equipment, ambience, and placement. The purpose of ergonomics is to maximize productivity by increasing safety, improving work quality, reducing operator fatigue and discomfort, and decreasing the risk of work -related musculoskeletal disorders (MSDs).^1-3

Biomechanical Analysis Of Concealed Pack Load Influences On Terrorist Gait Signatures Derived From Gröbner Basis Theory, Sean S. Kohles, Anum Barki, Kimberly D. Kendricks, Ronald F. Tuttle

Biology Faculty Publications and Presentations

This project examines kinematic gait parameters as forensic predictors of the influence associated with individuals carrying concealed weighted packs up to 20% of their body weight. An initial inverse dynamics approach combined with computational algebra provided lower limb joint angles during the stance phase of gait as measured from 12 human subjects during normal walking. The following paper describes the additional biomechanical analysis of the joint angle data to produce kinetic and kinematic parameters further characterizing human motion. Results include the rotational velocities and accelerations of the hip, knee, and ankle as well as inertial moments and kinetic energies produced …

Novel Computational Approaches Characterizing Knee Physiotherapy, Wangdo Kim, Antonio P. Veloso, Duarte Araújo, Sean S. Kohles

Biology Faculty Publications and Presentations

A knee joint’s longevity depends on the proper integration of structural components in an axial alignment. If just one of the components is abnormally off-axis, the biomechanical system fails, resulting in arthritis. The complexity of various failures in the knee joint has led orthopedic surgeons to select total knee replacement as a primary treatment. In many cases, this means sacrificing much of an otherwise normal joint. Here, we review novel computational approaches to describe knee physiotherapy by introducing a new dimension of foot loading to the knee axis alignment producing an improved functional status of the patient. New physiotherapeutic applications …

Empirical Models Of Scalp-Eeg Responses Using Non-Concurrent Intracranial Responses, Komalpreet Kaur, Jerry J. Shih, Dean J. Krusienski

Electrical & Computer Engineering Faculty Publications

Objective- This study presents inter-subject models of scalp-recorded electroencephalographic (sEEG) event-related potentials (ERPs) using intracranially recorded ERPs from electrocorticography and stereotactic depth electrodes in the hippocampus, generally termed as intracranial EEG (iEEG).

Approach- The participants were six patients with medically-intractable epilepsy that underwent temporary placement of intracranial electrode arrays to localize seizure foci. Participants performed one experimental session using a brain-computer interface matrix spelling paradigm controlled by sEEG prior to the iEEG electrode implantation, and one or more identical sessions controlled by iEEG after implantation. All participants were able to achieve excellent spelling accuracy using sEEG, four of the participants …

Detection And Control Of Small Civilian Uavs, Matthew Peacock

Theses : Honours

With the increasing proliferation of small civilian Unmanned Aerial Vehicles (UAVs), the threat to critical infrastructure (CI) security and privacy is now widely recognised and must be addressed. These devices are easily available at a low cost, with their usage largely unrestricted allowing users to have no accountability. Further, current implementations of UAVs have little to no security measures applied to their control interfaces. To combat the threat raised by small UAVs, being aware of their presence is required, a task that can be challenging and often requires customised hardware.

This thesis aimed to address the threats posed by the …

Neutrosophic Logic Approaches Applied To ”Rabot” Real Time Control, Alexandru Gal, Luige Vladareanu, Florentin Smarandache, Hongnian Yu, Mincong Deng

Branch Mathematics and Statistics Faculty and Staff Publications

In this paper we present a way of deciding which control law should operate at a time for a mobile walking robot. The proposed deciding method is based on the new research field, called Neutrosophic Logic. The results are presented as a simulated system for which the output is related to the inputs according to the Neutrosophic Logic.

Fault Location Algorithms, Observability And Optimality For Power Distribution Systems, Wanjing Xiu

Theses and Dissertations--Electrical and Computer Engineering

Power outages usually lead to customer complaints and revenue losses. Consequently, fast and accurate fault location on electric lines is needed so that repair work can be carried out as fast as possible.

Chapter 2 describes novel fault location algorithms for radial and non-radial ungrounded power distribution systems. For both types of systems, fault location approaches using line to neutral or line to line measurements are presented. It’s assumed that network structure and parameters are known, so that during-fault bus impedance matrix of the system can be derived. Functions of bus impedance matrix and available measurements at substation are formulated, …

Prediction Model To Estimate The Zero Crossing Point For Faulted Waveforms, Md. Shakawat Hossan

Theses and Dissertations--Electrical and Computer Engineering

In any power system, fault means abnormal flow of current. Insulation breakdown is the cause of fault generation. Different factors can cause the breakdown: Wires drifting together in the wind, Lightning ionizing air, wires with contacts of animals and plants, Salt spray or pollution on insulators. The common type of faults on a three phase system are single line-to-ground (SLG), Line-to-line faults (LL), double line-to-ground (DLG) faults, and balanced three phase faults. And these faults can be symmetrical (balanced) or Unsymmetrical (imbalanced).In this Study, a technique to predict the zero crossing point has been discussed and simulated. Zero crossing point …

Robomirror: A Simulated Mirror Display With A Robotic Camera, Yuqi Zhang

Theses and Dissertations--Electrical and Computer Engineering

Simulated mirror displays have a promising prospect in applications, due to its capability for virtual visualization. In most existing mirror displays, cameras are placed on top of the displays and unable to capture the person in front of the display at the highest possible resolution. The lack of a direct frontal capture of the subject's face and the geometric error introduced by image warping techniques make realistic mirror image rendering a challenging problem. The objective of this thesis is to explore the use of a robotic camera in tracking the face of the subject in front of the display to …

Test 2087: Challenger Mt755e, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Dynamic Testing Procedures For Performance Assessment Of Nuclear Fuel Rods, Travis M. Adams

Honors Theses and Capstones

Existing transportation probabilistic risk assessment for spent nuclear fuel in the United States is based on short-term (decades) on-site storage at power plants before transport. Updated risk assessment estimates will be required as extended on-site storage (centuries) and higher burnup levels in fuel become standard. Nuclear fuel rods under these two conditions are more brittle than rods from short-term storage and intermediate burnup due to several mechanisms, including hydrogen embrittlement. Development of risk assessment requires characterizations of dynamic behavior of these degraded rods under transportation scenarios. This Honors thesis provides an initial literature review for a larger project that will …

Effects Of Sodium Hydroxide Pretreatment On Structural Components Of Biomass, Alicia A. Modenbach, Sue E. Nokes

Biosystems and Agricultural Engineering Faculty Publications

Pretreatment is a unit operation in the conversion of biomass to valuable products that utilizes various combinations of conditions, including chemicals, heat, pressure, and time, to reduce the recalcitrance of lignocellulose. Many such pretreatments have been developed over the years, as the operating conditions can be adapted so that lignocellulose is modified in ways unique to each pretreatment. By tailoring pretreatment conditions to achieve these modifications, the types of final products produced can be controlled. The purpose of this review is to provide a consolidated source of information for sodium hydroxide effects on lignocellulose. The structural characteristics of lignocellulose and …

Parametric Scramjet Analysis, Jongseong Choi

Electronic Theses and Dissertations

The performance of a hypersonic flight vehicle will depend on existing materials and fuels; this work presents the performance of the ideal scramjet engine for three different combustion chamber materials and three different candidate fuels. Engine performance is explored by parametric cycle analysis for the ideal scramjet as a function of material maximum service temperature and the lower heating value of jet engine fuels. The thermodynamic analysis is based on the Brayton cycle as similarly employed in describing the performance of the ramjet, turbojet, and fanjet ideal engines. The objective of this work is to explore material operating temperatures and …

A New Algorithm For Piecewise Affine System Identification And Its Application To A Mems Switch, Niel Canty

Theses

Over the past ten years, hybrid systems, and piecewise affine (PWA) systems in particular have been viewed as viable option for modelling nonlinear systems. Many methods have been developed to cater for the identification of a PWA model from input/output data. This thesis focuses on the clustering based identification approach. This method uses a Least Squares (LS) identification algorithm which, in this thesis, is shown to perform poorly in practice. The clustering based algorithm is also limited by the number of initialisation parameters that need to be chosen. These parameters have a significant influence on the resulting PWA model accuracy, …

A Decision Making Tool For Sustainable Design In Construction, Enda Collins

Theses

This report defines sustainability and sustainable development before any research is carried out. This is necessary so that the research carried out further in the report makes sense and there is a reason for including such items in this report. The need for this project and what the project aims to achieve is also highlighted in the introduction of this report.

Sustainability is made up of three equal parts; social, economic and environmental. This report goes through each item and gives examples of each type of development. Having discussed sustainability in a broad sense the report then focuses on Legislation …

An Investigation And Evaluation Of The Proposed Harbour Development In Bantry Bay, Cork, Shane O'Flynn

Theses

RPS Group was appointed by Bantry Bay Harbour Commissioners to develop a master plan for a waterfront development in Bantry Bay Inner Harbour. It has been proposed that the inner harbour be dredged to a sufficient water depth to allow the entrance of marine craft. The purpose of the thesis is to evaluate and discuss the decisions regarding the environmental impacts that a harbour development would have on Bantry Bay. This research investigates the feasibility of alternative dredge treatment processes used in the Bantry Bay Inner Harbour Development. This research investigates the possibility of reusing the dredge material on site, …

Impact Of Run-Off Coefficients On Urban Drainage Design, Ross O'Sullivan

Theses

This study assesses the impacts that runoff coefficients have on an urban drainage design. The first part of the report reviews how drainage design is carried out. This assesses the traditional hand calculations method, where eharts and graphs are used, versus the more modem approach of using a computer modelling system such as WinDes. Both approaches were reviewed, as both will be used to design drainage systems at a further stage in the project. The objective of this projeet is to see how runoff eoefficients impact on urban drainage design. The methodology used to determine this, is to test six …

Managing Risk Perception In Adventure Tourism Activities, Ann O'Connor

Theses

The Adventure Tourism Industry is a customer service industry where product development and presentation is propelled by the clients' needs and desires. The majority of people who participate in adventure tourism activities are novices and have no prior experience or relevant skills. It is this market of 'no skills required' which is the focus of the commercial adventure tourism industry. As there are inherent risks involved in all adventure activities, risk, risk perception and risk management are key skills for the Adventure Activity Provider and Guide. Risk however is multidimensional, made up of physical risk components and subjective risk components. …

Testing And Analysis Of An Alternative Connection Method In Closed Panel Timber Frame Domestic Construction, Brendan Towey

Masters

Construction practices continue to evolve in tandem with the requirements for more energy efficient buildings, materials and construction methods. This steady and progressive move towards the development of the industry and its products comes, not in leaps and bounds, but in incremental advances across all areas of construction. The research detailed in this project is one such advancement. Timber frame construction has been in existence for centuries and its tried and tested methods have been utilised worldwide in both domestic and industrial building. In recent times, standard open panel timber frame construction has been enhanced by the development of closed …

Comparative Analysis Of Research Priorities For Technology Education, Gene Martin, John Ritz

STEMPS Faculty Publications

This study compares and contrasts the most relevant research priorities identified through two Delphi studies by the authors. The panels of experts used in these studies, an international and a U.S. study group, were asked to identify important topics to guide future research studies for the school subject of technology education. Both panels sought to determine the most relevant issues that need to be researched related to K-12 technology education and preparation for teaching this school subject. This study reports the similarities of research priorities identified by both expert panels, then contrasts the major differences that the groups identified for …

Effect Of Electrospun Nanofibers On The Short Beam Strength Of Laminated Fiberglass Composite, Dattaji K. Shinde

Dissertations

High specific modulus and strength are the most desirable properties for the material used in structural applications. Composite materials exhibit these properties and over the last decade, their usage has increased significantly, particularly in automotive, defense, and aerospace applications. The major cause of failures in composite laminates is due to delaminations. Delamination in composite laminates can occur due to fatigue, low velocity impact and other loadings modes. Conventional methods like “through-the-thickness stitching” or “Z-Pinning” have limitations for improving flexural and interlaminar properties in woven composites due to the fact that while improving interlaminar properties, the presence of stitches or Z …

Design And Analysis Of Reconfigurable Sensing Antennas For Wireless Sensing Applications, Qian Qiao

Electronic Theses and Dissertations

Reconfiguration sensing antenna (rsa) is a novel antenna concept, which not only can transmit or receive radio waves but also can sense the surrounding environment. The environment sensing is realized by reconfiguring the antenna's characteristics, such as resonant frequency, and radar cross section (rcs). The rsas possess the advantages of passive and low cost, which make them suitable for the large-scale wireless sensing networks (wsns) deployment. In this dissertation, the rsas concept is demonstrated, and two sensing mechanisms performed in the rsas are investigated. In order to verify these sensing mechanisms, four rsas are designed, analyzed, and measured. All the …

Repeated Load Relaxation Testing Of Pure Polycrystalline Nickel At Room Temperature Using Nanoindentation, D. E. Stegall, M. A. Mamun, B. Crawford, A, A. Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

We present the results of repeated relaxation tests using nanoindentation to derive the activation volume of the dislocation velocity and the ratios of the dislocation density and dislocation velocity. An experimental technique, based on classical uniaxial relaxation experiments, was developed to establish a constant strain during repeated load relaxation transients and then to calculate the stiffness of unloading, and therefore the hardness, across the transients with acceptable results. We found that the activation volume of the dislocation velocity from our nanoindentation methodology was in good agreement when compared to the same reported for uniaxial experiments. © 2014 AIP Publishing LLC.

Relative Motion Guidance, Navigation And Control For Autonomous Orbital Rendezvous, Mohamed Okasha, Brett Newman

Mechanical & Aerospace Engineering Faculty Publications

In this paper, the dynamics of the relative motion problem in a perturbed orbital environment are exploited based on Gauss’ variational equations. The relative coordinate frame (Hill frame) is studied to describe the relative motion. A linear high fidelity model is developed to describe the relative motion. This model takes into account primary gravitational and atmospheric drag perturbations. In addition, this model is used in the design of a control, guidance, and navigation system of a chaser vehicle to approach towards and to depart from a target vehicle in proximity operations. Relative navigation uses an extended Kalman flter based on …

Placement Of Mode And Wavelength Converters For Throughput Enhancement In Optical Networks, Ruaa Abdulrahman

Electronic Theses and Dissertations

The success of recent experiments to transport data using combined wavelength division multiplexed (WDM) and mode-division multiplexed (MDM) transmission has generated optimism for the attainment of optical networks with unprecedented bandwidth capacity, exceeding the fundamental Shannon capacity limit attained by WDM alone. Optical mode converters and wavelength converters are devices that can be placed in future optical nodes (routers) to prevent or reduce the connection blocking rate and consequently increase network throughput. In this thesis, the specific problem of the placement of mode converters (MC) and mode-wavelength converters (MWC) in combined mode and wavelength division multiplexing (MWDM) networks is investigated. …