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Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering

An Investigation Of Metaheuristics Using Path- Relinking On The Quadratic Assignment Problem, Thashika Rupasinghe Dec 2010

An Investigation Of Metaheuristics Using Path- Relinking On The Quadratic Assignment Problem, Thashika Rupasinghe

All Dissertations

The Quadratic Assignment Problem (QAP) is a widely researched, yet complex, combinatorial optimization problem that is applicable in modeling many real-world problems. Specifically, many optimization problems are formulated as QAPs. To resolve QAPs, the recent trends have been to use metaheuristics rather than exact or heuristic methods, and many researchers have found that the use of hybrid metaheuristics is actually more effective. A newly proposed hybrid metaheuristic is path relinking (PR), which is used to generate solutions by combining two or more reference solutions. In this dissertation, we investigated these diversification and intensification mechanisms using QAP. To satisfy the extensive …


Modeling Microbial And Nutrient Dynamics In Zero-Discharge Aquaculture Systems, Kendall Kirk Dec 2010

Modeling Microbial And Nutrient Dynamics In Zero-Discharge Aquaculture Systems, Kendall Kirk

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A finite element, finite difference model was developed to predict nutrient and microbial dynamics in recirculating aquaculture systems. Total ammonia nitrogen, nitrite, nitrate, chemical oxygen demand, and dissolved oxygen concentrations are predicted in addition to growth and decay of algae, Nitrosomonas, Nitrobacter, denitrifying heterotrophs, and aerobic heterotrophs. Inputs to the model include temperature, photosynthetically available radiation, feed application rate, pH, aeration/mixing energy, water exchange configuration, water exchange rate, tilapia biomass, and dissolved oxygen concentration. Up to 10 exchanged units may be included, user-definable as continuous stirred tank reactors or sequencing batch reactors. Demonstration of the model's utility was demonstrated through …


Analysis Of Part Consolidation Techniques For Automotive Body In White Panels Based On Advanced Sheet Metal Forming Technologies, Harish Thiruvengadam Dec 2010

Analysis Of Part Consolidation Techniques For Automotive Body In White Panels Based On Advanced Sheet Metal Forming Technologies, Harish Thiruvengadam

All Theses

The automotive industry is looking to move from mass production to mass customization in order to manufacture and sell a variety of products in different markets on a global scale. This requires a robust and cost effective manufacturing system which would help design new products in the shortest possible lead time. This thesis tries to investigate the current sheet metal forming process for body in white, identify the limitations and propose an alternative which would help the industry cut down product lead time and costs. Decision making tools are used to identify the technical requirements of a BIW manufacturing system …


A Meta-Analysis Of Human Factors Analysis And Classification System Causal Factors: Establishing Benchmarking Standards And Human Error Latent Failure Pathway Associations In Various Domains, Katherine Berry Dec 2010

A Meta-Analysis Of Human Factors Analysis And Classification System Causal Factors: Establishing Benchmarking Standards And Human Error Latent Failure Pathway Associations In Various Domains, Katherine Berry

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Many models of accident investigation have been created and have served as the basis for other tools and techniques. One of the most prominent techniques, Reason's Swiss Cheese Model (1990), is based on the idea of active and latent failures. Expanding on this idea, the Human Factors Analysis and Classification System (HFACS) was created with the idea to associate contributing factors and errors (Wiegmann & Shappell, 2003).
While HFACS has been frequently applied in the field of aviation in literature, other industry types are under-represented. Seventeen data sources encompassing various industry types were collected and included in this dissertation analysis. …


Assortment Planning For Multiple Quality Levels Using Locational Choice, Mark Mcelreath Dec 2010

Assortment Planning For Multiple Quality Levels Using Locational Choice, Mark Mcelreath

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Assortment planning is the process in which a retailer selects a product line to offer to customers and is a key determinant of a retailer's profit. We consider the assortment planning problem using a locational choice model for customer product selection and allow for both horizontal and vertical product differentiation. When the distribution of customer preference is unimodal, the optimal solutions for this problem are unknown. We propose two solution philosophies for generating product assortments. First, we introduce a metaheuristic representation for the problem and test the performance of three metaheuristic techniques. We suggest that a tabu search or genetic …


Comprehensive Thermal Modeling Of Power Split Hybrid Power-Train And Electronics, Abdel Mayyas Dec 2010

Comprehensive Thermal Modeling Of Power Split Hybrid Power-Train And Electronics, Abdel Mayyas

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Hybrid electric vehicle (HEV) uses both internal combustion engine (ICE) with an electric system. The combination of the electric power train with the ICE is intended to achieve both better fuel economies than the conventional vehicles and better performance. Several types of HEV exist with different layouts. Recent HEVs' make use of regenerative braking, which converts the vehicles' kinetic energy into electric energy instead of wasting it as heat as conventional brakes do. A hybrid-electric is more fuel efficient than ICE and has less environmental impact.
The new HEV with its new Key Characteristics and Configurations (i.e. Mechanical complexity, Multiple …


Order Picking And Storage Using Stackable Pallets In A Warehouse, Ahmed Hassan Aly Dec 2010

Order Picking And Storage Using Stackable Pallets In A Warehouse, Ahmed Hassan Aly

All Dissertations

Quarter Billion dollars could be saved annually by double stacking pallets. A forklift storing 100 double stacked pallets saves 2.5 working hours versus single pallets. More than one billion pallets and cases handled between Wal-Mart distribution centers according to BEA White Paper (2006) [1], assume only 500 million were stackable pallets. This translates to 12.5 million working hours. If a forklift driver earns $20 per hour, then $250 million can be saved.
Moreover, handling double stacked pallets takes up to 46 % of total time to pick and store. This is a significant element that was ignored in literature. All …


Sensor Based Nitrogen Management For Cotton Production In Coastal Plain Soils, Wesley Porter Aug 2010

Sensor Based Nitrogen Management For Cotton Production In Coastal Plain Soils, Wesley Porter

All Theses

The main objective of this four year study was to develop, refine, and employ sensor-based algorithims to determine the mid season nitrogen requirements for production of irrigated and dryland cotton (Gossypium hirsutum L.) in Coastal Plains soils. The secondary objective of the project was to develop and test equipment for variable rate application of nitrogen to commerical cotton fields utilizing the developed algorithim. Two different production fields at Clemson's Edisto Research and Education Center near Blackville, SC were used. One field, equiped with an overhead irrigation system, was used during the 2007 and 2010 production seasons to develop the algorithm …


Remote Usability Testing - A New Approach Facilitated By Virtual Worlds, Kapil Chalil Madathil Aug 2010

Remote Usability Testing - A New Approach Facilitated By Virtual Worlds, Kapil Chalil Madathil

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Synchronous remote usability testing, involves a facilitator conducting a usability test in real time, interacting with a participant who is remote. This study proposes a new methodology for conducting these studies using a three-dimensional virtual world, Wonderland, and compares it with two other commonly used synchronous usability test methods: the traditional lab approach and WebEx, a web-based conferencing and screen sharing approach.
The study involved 48 participants in total, 36 test subjects and 12 test facilitators. These 36 were equally divided among the three environments with the 12 test facilitators being paired with one participant in each of the environments. …


Simulation And Mathematical Modeling To Support Community-Wide Evacuation Decisions For Multiple Population Groups, Jun Duanmu Aug 2010

Simulation And Mathematical Modeling To Support Community-Wide Evacuation Decisions For Multiple Population Groups, Jun Duanmu

All Dissertations

Evacuating a large population from an at-risk area has been the subject of extensive research over the past few decades. In order to measure trip completion and total evacuation times accurately, most researchers have implemented some combination of simulation and optimization methods to provide vehicular flow and congestion data. While the general at-risk population comprises the majority of travelers on the road network, there are often specific groups to consider when assessing the ability to evacuate an entire population. In particular, healthcare facilities (e.g., hospitals) may require evacuation, and the trip times may become an important health issue for patients …


Principal Component Analysis Based Image Fusion Routine With Application To Stamping Split Detection, Yi Zhou Aug 2010

Principal Component Analysis Based Image Fusion Routine With Application To Stamping Split Detection, Yi Zhou

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This dissertation presents a novel thermal and visible image fusion system with application in online automotive stamping split detection. The thermal vision system scans temperature maps of high reflective steel panels to locate abnormal temperature readings indicative of high local wrinkling pressure that causes metal splitting. The visible vision system offsets the blurring effect of thermal vision system caused by heat diffusion across the surface through conduction and heat losses to the surroundings through convection. The fusion of thermal and visible images combines two separate physical channels and provides more informative result image than the original ones.
Principal Component Analysis …


Estimation And Control Of Robotic Radiation-Based Processes, Fan Zeng Aug 2010

Estimation And Control Of Robotic Radiation-Based Processes, Fan Zeng

All Dissertations

This dissertation presents a closed-loop control and state estimation framework for a class of distributed-parameter processes employing a moving radiant actuator. These radiation-based processes have the potential to significantly reduce the energy consumption and environmental impact of traditional industrial processes. Successful implementation of these approaches in large-scale applications requires precise control systems. This dissertation provides a comprehensive framework for: 1) integration of trajectory generation and feedback control, 2) online distributed state and parameter estimation, and 3) optimal coordination of multiple manipulated variables, so as to achieve elaborate control of these radiation-based processes for improved process quality and energy efficiency.
The …


Prioritizing Patients For Emergency Evacuation From A Healthcare Facility, Ashley Childers Aug 2010

Prioritizing Patients For Emergency Evacuation From A Healthcare Facility, Ashley Childers

All Dissertations

The success of a healthcare facility evacuation depends on communication and decision-making at all levels of the organization, from the coordinators at incident command to the clinical staff who actually carry out the evacuation. One key decision is the order in which each patient is chosen for evacuation. While the typical planning assumption is that all patients are to be evacuated, there may not always be adequate time or resources available to move all patients. In these cases, prioritizing or ordering patients for evacuation becomes an extremely difficult decision to make. These decisions should be based on the current state …


Maximizing Throughput Using Dynamic Resource Allocation And Discrete Event Simulation, Gregory Gunn May 2010

Maximizing Throughput Using Dynamic Resource Allocation And Discrete Event Simulation, Gregory Gunn

All Theses

This research studies a serial two stage production system with two flexible servers which can be dynamically assigned to either station. This is modeled using discrete event simulation and more specifically the Arena software package by Rockwell. The goal is to determine dynamic allocation policies based upon the inventory level at each station to maximize the throughput of finished goods out of the system. This model adds to previous work by including actual switching time. The effect of the pre-emptive resume assumption is gauged, and the effectiveness of the OptQuest optimization package is also tested. Studies are conducted to determine …


'Transfer Effect Study Of A Virtual Borescope In Training Aircraft Maintenance Technicians', Melissa Dorlette Paul May 2010

'Transfer Effect Study Of A Virtual Borescope In Training Aircraft Maintenance Technicians', Melissa Dorlette Paul

All Theses

The Federal Aviation Administration (FAA) has acknowledged training as an important tactic to improve the trustworthiness of inspection. This study was conducted to test the transfer of the skills learned with a simulator into the real world. For this purpose, data from seventeen students in the AMT program of Greenville Technical College was analyzed. Objective data was taken to assess the group's performance on the simulator after each session of training. The comparison between two groups was made using objective data, collected while the subjects went through a test on a real engine and using the real borescope, and subjective …