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Predicting The Thermal Performance For The Multi-Objective Vehicle Underhood Packing Optimization Problem, Ravi Teja Katragadda Aug 2011

Predicting The Thermal Performance For The Multi-Objective Vehicle Underhood Packing Optimization Problem, Ravi Teja Katragadda

All Theses

The ever increasing demands towards improvement in vehicle performance and passenger comfort have led the automotive manufacturers to further enhance the design in the early stages of the vehicle development process. Though, these design changes enhance the overall vehicle performance to an extent, the placement of these components under the car hood also plays a vital role in increasing the vehicle performance. The study of the placement of these components in an automobile underhood forms a 3-Dimensional packaging problem. In the past, a study on the automobile underhood packaging problem was conducted and a multi objective optimization routine with three …

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Friction Stir Welding (Fsw) Process Modeling And Fsw Joint Design For Blast Survivable Structures, Anand Hariharan Aug 2011

Friction Stir Welding (Fsw) Process Modeling And Fsw Joint Design For Blast Survivable Structures, Anand Hariharan

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In order to satisfy the need for better ballistic performance against lethal threats, new grades of Titanium (e.g. Ti-6Al-4V) and Aluminum (e.g. AA5083) alloys are being employed in the design of blast survivable structures. These better performing alloys are not readily amenable to conventional welding process or result in inferior welds when joined using conventional welding process. On the other hand, Friction Stir Welding (FSW), a relatively new welding process, has been found to be successful in producing good quality welds in these alloys. FSW also offers better weld performance in comparison with the conventional welding process. But the methodology …

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A Method For Evaluating Manufacturing Change In Engineering Design, Christopher Brooks Aug 2011

A Method For Evaluating Manufacturing Change In Engineering Design, Christopher Brooks

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Design changes are a frequent occurrence over the life of a product that may be initiated by an update to the product functionality, new customer needs, or generational improvements. The costs associated with these changes are undesirable, and are often times greatly inflated by additional, unanticipated changes that result from change propagating throughout the system. Propagation paths occur when an initiating change to a component necessitates subsequent changes to coupled components, as the change continues to propagate throughout the product architecture. The nature of this change propagation is challenging to characterize and accurately predict. To address this issue, a change …

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Sediment Based Turbidity Analyses For Representative South Carolina Soils, Katherine Resler Aug 2011

Sediment Based Turbidity Analyses For Representative South Carolina Soils, Katherine Resler

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Construction activities have been recognized to have significant impacts on the environment. Excess sediment from construction sites is frequently deposited into nearby surface waters, negatively altering the chemical, physical and biological properties of the water body. This environmental concern has led to strict laws concerning erosion and sediment control, such as imposing permit conditions that limit the concentration of suspended solids that can be present in effluent water from construction sites. However, sediment concentration measurements are not routinely used to detect and correct short-term problems or permit violations because laboratory analysis of sediment concentrations is time-consuming and costly. Nevertheless, timely, …

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Substrate Topography Design And Fabrication For Osteoblast And Dental Pulp Stem Cells Studies, Gloria Chen Aug 2011

Substrate Topography Design And Fabrication For Osteoblast And Dental Pulp Stem Cells Studies, Gloria Chen

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Research for cell guidance based tissue engineering has rapidly grown due to the increasing interest in tissue engineering and reconstructive medicine applications, such as cranial reconstruction. Many research teams have begun the process of identifying what factors influence cell behavior (including cell growth, proliferation, alignment and spreading). Published studies have pointed to the influence of the cell medial pH, substrate stiffness, chemistry and topography. Conclusive results are often hard to identify since researchers often vary many of these factors simultaneously and it is hard to decouple individual factor influence. These reports also points out that the cellular response can be …

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Extracting Depth Information From Stereo Vision System, Using A Correlation And A Feature Based Methods, Mahmoud Abdelhamid Aug 2011

Extracting Depth Information From Stereo Vision System, Using A Correlation And A Feature Based Methods, Mahmoud Abdelhamid

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This thesis presents a new method to extract depth information from stereo-vision acquisitions using a feature and a correlation based approaches. The main implementation of the proposed method is in the area of Autonomous Pick & Place, using a robotic manipulator. Current vision-guided robotics are still based on a priori training and teaching steps, and still suffer from long response time.
The study uses a stereo triangulation setup where two Charged Coupled Devices CCDs are arranged to acquire the scene from two different perspectives. The study discusses the details of two methods to calculate the depth; firstly a correlation matching …

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Assessing The Influence Of Hemlock Mortality On Streams Due To Hemlock Woolly Adelgid Infestation, Celestine Che Aug 2011

Assessing The Influence Of Hemlock Mortality On Streams Due To Hemlock Woolly Adelgid Infestation, Celestine Che

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For the past 30 years eastern hemlock forests in the US have been declining rapidly due to damage caused by a destructive exotic insect pest, the hemlock woolly adelgid, Adelges tsugae Annand (Homoptera: Adelgidae), a native of the Far East. The impact of the loss of hemlocks, which occur naturally in cool hillside and ravine environments along streams, is poorly understood. The loss of these trees has the potential to cause significant environmental disturbance by changing energy inputs into streams, stream microclimates, and aquatic macroinvertebrate communities.
In May 2009, after hemlock mortality due to A. tsugae was already severe, I …

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Combining Procedural And Hand Modeling Techniques For Creating Animated Digital 3d Natural Environments, Hubert Smith Aug 2011

Combining Procedural And Hand Modeling Techniques For Creating Animated Digital 3d Natural Environments, Hubert Smith

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This thesis focuses on a systematic solution for rendering 3D photorealistic natural environments using Maya's procedural methods and ZBrush. The methods used in this thesis started with comparing two industry specific procedural applications, Vue and Maya's Paint Effects, to determine which is better suited for applying animated procedural effects with the highest level of fidelity and expandability. Generated objects from Paint Effects contained the highest potential through object attributes, texturing and lighting. To optimize results further, compatibility with sculpting programs such as ZBrush are required to sculpt higher levels of detail. The final combination workflow produces results used in the …

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The Effect Of Prior Experiences And Sequence Of Instruction Upon Preservice Teachers' Pedagogical Beliefs And Mathematical Knowledge For Teaching, Benjamin Sloop Aug 2011

The Effect Of Prior Experiences And Sequence Of Instruction Upon Preservice Teachers' Pedagogical Beliefs And Mathematical Knowledge For Teaching, Benjamin Sloop

All Dissertations

This study investigated the effects of sequence of instruction in a laboratory-based mathematics content course for elementary teachers on preservice teachers' (PSTs') pedagogical beliefs and Mathematical Knowledge for Teaching (MKT) through a quasi-experimental design in which the order of laboratory tasks and explanations of content was altered between sections for a given unit and between units within a given section. This study also investigated the prior experiences a group of preservice elementary teachers shared as students of mathematics and examined how these experiences related to their beliefs regarding effective pedagogy through a phenomenology. Additionally, the perspective of an experienced instructor, …

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Bridging The Gap Between Structures And Properties: An Investigation And Evaluation Of Students' Representational Competence, Sonia Underwood Aug 2011

Bridging The Gap Between Structures And Properties: An Investigation And Evaluation Of Students' Representational Competence, Sonia Underwood

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The heart of learning chemistry is the ability to connect a compound's structure to its function; Lewis structures provide an essential link in this process. In many cases, their construction is taught using an algorithmic approach, containing a set of step-by-step rules. We believe that this approach is in direct conflict with the precepts of meaningful learning. From a sequential, mixed methods study, we found that students have much difficulty constructing these structures and that the step-by-step rules do not make use of students' relevant prior knowledge. This causes students to develop 'home grown' rules when unsure of how to …

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Semifluorinated Aromatic Ether Polymers Segmented With Polyethylene Glycol (Peg), Dakarai Brown Aug 2011

Semifluorinated Aromatic Ether Polymers Segmented With Polyethylene Glycol (Peg), Dakarai Brown

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Aromatic trifluorovinyl ether (TFVE) monomers are the precursors for perfluorocyclobutyl (PFCB) aryl ether polymers and fluoroethylene/vinylene alkyl/aryl ether (FAE) polymers. PFCB aryl ether polymers are prepared by 2π + 2π cycloaddition of aromatic TFVE monomers. FAE polymers are prepared by nucleophilic addition of dual functional aryl or alkyl alcohols to aryl TFVE monomers. PFCB aryl ether and FAE polymers are amorphous, have excellent processability, high thermal stability, optical clarity, and tunability using a variety of (co)monomers. In this dissertation several novel monomers, polymers, and blends were prepared by incorporation of polyethylene glycol (PEG) or PEG precursors.
Chapter 1 contains the …

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Biological And Ecological Responses To Carbon-Based Nanomaterials, Tatsiana Ratnikova Aug 2011

Biological And Ecological Responses To Carbon-Based Nanomaterials, Tatsiana Ratnikova

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Nanotechnology has been undergoing tremendous development in recent decades, driven by realized perceived applications of nanomaterials in electronics, therapeutics, imaging, sensing, environmental remediation, and consumer products. Along with these developments there have been increased evidences that engineered nanomaterials are often associated with hazardous effects they invoke in biological and ecosystems through intentional designs or unintentional discharge. Consequently there is a crucial need for documenting and understanding the interactions between nanoparticles and biological and ecosystems. This dissertation is aimed at bridging such a knowledge gap by examining the biological and ecological responses to carbon nanoparticles, a major class of nanomaterials which …

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Downstream Resource Allocation In Docsis 3.0 Channel Bonded Networks, Scott Moser Aug 2011

Downstream Resource Allocation In Docsis 3.0 Channel Bonded Networks, Scott Moser

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Modern broadband internet access cable systems follow the Data Over Cable System Interface Specification (DOCSIS) for data transfer between the individual cable modem (CM) and the Internet. The newest version of DOCSIS, version 3.0, provides an abstraction referred to as bonding groups to help manage bandwidth and to increase bandwidth to each user beyond that available within a single 6MHz. television channel. Channel bonding allows more than one channel to be used by a CM to provide a virtual channel of much greater bandwidth. This combining of channels into bonding groups, especially when channels overlap between more than one bonding …

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Persuasive Packaging: An Eye-Tracking Approach To Design, Rupert Hurley Aug 2011

Persuasive Packaging: An Eye-Tracking Approach To Design, Rupert Hurley

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This dissertation details the development of a consensus-centered strategy for managing packaging design projects that enables designers from various fields to participate (seriously play) in the development process. The Work/Flow developed was quantified though a series of empirical eye-tracking experiments to determine if objects produced through the system resulted in longer fixation durations than the control. It was determined that packages developed through the Work/Flow were significantly more persuasive than the control (P < 0.0005).
The second experiment observed the effectiveness of designs produced through the Work/Flow in respect to the competitive retail array. Out of three product categories tested, one package …

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Understanding The Role Of Embeddedness In Shaping It Professional Behavior, Michael Dinger Aug 2011

Understanding The Role Of Embeddedness In Shaping It Professional Behavior, Michael Dinger

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This dissertation studies how information technology (IT) professionals become embedded and, in turn, how embeddedness influences organizational behaviors. Embeddedness refers to the extent to which an individual is attached to an organizational or professional setting. Traditionally, embeddedness is defined as having three components: social links, fit and sacrifice. We analyze the traditional conceptualization of embeddedness and identify weaknesses. As a result, we refine these three components to belongingness, fit and utility.
To deepen our understanding of embeddedness and its influence on organizational behavior, we develop a theory of embeddedness. We propose that embeddedness grows over time. As embeddedness increases, we …

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Conjugated Polymers And Inter-Chromophore Interactions: Synthesis, Photophysical Characterization And Application, Anshuman Mangalum Aug 2011

Conjugated Polymers And Inter-Chromophore Interactions: Synthesis, Photophysical Characterization And Application, Anshuman Mangalum

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Ever since the discovery of conducting polymers (CPs)in the late 1970s, organic conjugated materials and polymers is one of the most popular and fascinating research area among the scientists due to the remarkably unique properties and broad range of applications of (CPs), notably organic photovoltaic (OPVs), organic or polymer based light emitting devices (OLEDs / PLEDs), field effect transistors (FETs), nonlinear optical (NLO) devices and sensor for biologically relevant analytes, metal ions and anions. Optical properties of these materials depend on intra / interchromophoric interaction, geometry and relative orientation in space. Detailed study of such materials can also help us …

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Computational-Analysis Assisted Introduction Of Friction Stir Welding Into Development Of Light-Weight High-Survivability Military Vehicles, Guruprasad Arakere Aug 2011

Computational-Analysis Assisted Introduction Of Friction Stir Welding Into Development Of Light-Weight High-Survivability Military Vehicles, Guruprasad Arakere

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High strength aluminum alloys with superior blast/ballistic resistance against armor piercing (AP) threats and with high vehicle light-weighing potential are being increasingly used as military-vehicle armor. Due to the complex structure of these vehicles, they are commonly constructed through joining (mainly welding) of the individual components. Unfortunately, these alloys are not very amenable to conventional fusion based welding technologies (e.g. Gas Metal Arc Welding (GMAW)) and in-order to obtain high-quality welds, solid-state joining technologies such as Friction Stir Welding (FSW) have to be employed. However, since FSW is a relatively new and fairly complex joining technology, its introduction into advanced …

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Effects Of Surface States, Defects And Dopants On The Optical And Magnetic Properties Of Low-Dimensional Materials, Ramakrishna Podila Aug 2011

Effects Of Surface States, Defects And Dopants On The Optical And Magnetic Properties Of Low-Dimensional Materials, Ramakrishna Podila

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Nanomaterials have attracted the attention of researchers from various fields due to their unique features (that are otherwise absent in the bulk) such as quantum confinement, high surface to volume ratio, ability for surface modification etc. Since the discovery of fullerenes and carbon nanotubes, several synthesis techniques have been developed for nanomaterial growth. However, different control parameters in different synthesis techniques often result in nanostructures with varying defects that may alter their fundamental behavior. Such defects or disorder in the crystal lattice can lead to the disruption of lattice symmetry. The defect-induced symmetry lowering (or breaking) effects play a vital …

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The Effects Of Concrete-Representational-Abstract Sequenced Instruction On Struggling Learners Acquisition, Retention, And Self-Efficacy Of Fractions, Elizabeth Hughes Aug 2011

The Effects Of Concrete-Representational-Abstract Sequenced Instruction On Struggling Learners Acquisition, Retention, And Self-Efficacy Of Fractions, Elizabeth Hughes

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A growing body of research supports instructional strategies, such as concrete-representational-abstract (CRA) sequence, to teach mathematics to students at risk of failure, including those with disabilities. This study extends the current body of CRA research by analyzing the effects of CRA sequence of instruction on student achievement, and retention, and self-efficacy of performance on computations of fractions. Thirty-five students participated in this study. A series of repeated measures ANOVAs were performed to assess main effects and interaction effects for performance and self-efficacy of students in a control group who received traditional fractions instruction and a treatment group who received CRA …

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Predicting Yeast Synthetic Lethal Genetic Interactions Using Protein Domains, Bo Li Aug 2011

Predicting Yeast Synthetic Lethal Genetic Interactions Using Protein Domains, Bo Li

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Synthetic lethal genetic interaction (SLGI) is an important biological phenomenon. Such interactions are of interest as they can be used to predict function of unknown proteins and find drug targets or drug combinations. High throughput biological experiments enhance the capability in identifying genetic interactions, but the large amount of protein pairs still make the task of genome-wide identification of genetic interactions overwhelming. Computational based prediction of SLGIs is promising but still hampered by the unclear molecular mechanism of SLGIs.
Protein domains with conserved functions serve as the building blocks of proteins. The genetic interaction that occurs between a pair of …

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Contaminant Mass Transfer During Boiling In Fractured Geologic Media, Fei Chen Aug 2011

Contaminant Mass Transfer During Boiling In Fractured Geologic Media, Fei Chen

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Remediation of fractured geologic media contaminated with chlorinated volatile organic compounds that diffuse into the matrix is challenging using isothermal methods. Due to the low permeability of the matrix material and uncertainty of fracture networks, it is difficult to flush the system with any type of fluid or deliver remediation agents into the matrix. However, thermal methods have some promises. When the matrix is heated above water boiling temperature, depressurization in the fractures may trigger water boiling in the matrix, which, as a result, generates a large volumetric steam flow toward adjacent fractures, stripping the adsorbed or dissolved volatile contaminants …

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Inference In Reversible Markov Chains, Tara Steuber Aug 2011

Inference In Reversible Markov Chains, Tara Steuber

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This dissertation describes the research that we have done concerning
reversible Markov chains. We first present definitions for what it means
for a Markov chain to be reversible. We then give applications of where
reversible Markov chains are used and give a brief history of Markov chain
inference. Finally, two journal articles are found in the paper, one that
is already published and another which is currently being submitted.
The first article examines estimation of the one-step-ahead
transition probabilities in a reversible Markov chain on a countable state
space. A symmetrized moment estimator is proposed that exploits the
reversible structure. …

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Pseudocodewords Of Parity-Check Codes, Wittawat Kositwattanarerk Aug 2011

Pseudocodewords Of Parity-Check Codes, Wittawat Kositwattanarerk

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The success of modern algorithms for the decoding problem such as message-passing iterative decoding and linear programming decoding lies in their local nature. This feature allows the algorithms to be extremely fast and capable of correcting more errors than guaranteed by the classical minimum distance of the code. Nonetheless, the performance of these decoders depends crucially on the Tanner graph representation of the code. In order to understand this choice of representation, we need to analyze the pseudocodewords of the Tanner graph of a code. These pseudocodewords are outputs of local decoding algorithms which may not be legitimate codewords. In …

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Low-Resolution Vision For Autonomous Mobile Robots, Vidya Nariyambut Murali Aug 2011

Low-Resolution Vision For Autonomous Mobile Robots, Vidya Nariyambut Murali

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The goal of this research is to develop algorithms using low-resolution images to perceive and understand a typical indoor environment and thereby enable a mobile robot to autonomously navigate such an environment. We present techniques for three problems: autonomous exploration, corridor classification, and minimalistic geometric representation of an indoor environment for navigation.
First, we present a technique for mobile robot exploration in unknown indoor environments using only a single forward-facing camera. Rather than processing all the data, the method intermittently examines only small 32X24 downsampled grayscale images. We show that for the task of indoor exploration the visual information is …

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Modeling Of Strain Effect On Thermal And Electrical Transport Properties Of Si/Ge Nanocomposites And Its Applications, Yaoyao Xu Aug 2011

Modeling Of Strain Effect On Thermal And Electrical Transport Properties Of Si/Ge Nanocomposites And Its Applications, Yaoyao Xu

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Nanocomposites are composite materials which incorporate nanosized particles, platelets or fibers. The addition of nanosized phases into the bulk matrix can lead to significantly different material properties compared to their macrocomposite counterparts. Due to their extraordinary properties, nanocomposites promise new applications in many fields such as ultra-high strength and ultra-light automotive parts, non-linear optics, biomedical applications, sensors and actuators, and thermoelectric devices. The design and fabrication of nanocomposite structures, devices and systems can be accelerated by developing accurate and efficient computational tools that can describe the properties and behavior of the nanocomposites. However, the development of such tools is challenging …

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A Theoretical Investigation Examining Dna Conformational Changes And Their Effects On Glycosylase Function, Allyn Brice Aug 2011

A Theoretical Investigation Examining Dna Conformational Changes And Their Effects On Glycosylase Function, Allyn Brice

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Glycosylase enzymes initiate the process of base excision repair (BER) in order to prevent the irreversible modification of the genome. In the BER process a damaged DNA base is recognized, removed from the DNA sequence, and then the remaining abasic site is repaired. Glycosylase enzymes are responsible for the base recognition mechanism and catalysis of the base excision. One of the most studied glycosylase superfamilies is uracil DNA glycosylase (UDG). The UDG superfamily has demonstrated specificity for excising uracil, which is the deamination product of cytosine, from DNA sequences of prokaryotes and eukaryotes. Mismatch-specific uracil DNA glycosylase (MUG) is a …

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Metaheuristics For Hub Location Models, Ornurai Sangsawang Aug 2011

Metaheuristics For Hub Location Models, Ornurai Sangsawang

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In this research, we propose metaheuristics for solving two p-hub median problems.. The first p-hub median problem, which is NP-hard, is the uncapacitated single p-hub median problem (USApHMP). In this problem, metaheuristics such as genetic algorithms, simulated annealing and tabu search, are applied in different types of representations. Caching is also
applied to speed up computational time of the algorithms. The results clearly demonstrate that tabu search with a permutation solution representation, augmented with caching is the highest performing method, both in terms of solution quality and computational time among these algorithms for the USApHMP. We also investigate the performance …

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Anticipating U.S. Population-Level Health And Economic Impacts Using Discrete-Event Simulation To Guide Health Policy Decisions, Odette Reifsnider Aug 2011

Anticipating U.S. Population-Level Health And Economic Impacts Using Discrete-Event Simulation To Guide Health Policy Decisions, Odette Reifsnider

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This dissertation presents two applications of discrete-event simulation (DES) to represent clinical processes: (1) a model to quantify the risk of the maternal obese and diabetic intrauterine environment influence on progression to adult obesity and diabetes, and (2) a model to evaluate health and economic outcomes of different smoking cessation strategies. The first application considers the public health impact of the diabetic and obese intrauterine environment's effect on the prevalence of diabetes and obesity across subsequent generations. We first develop a preliminary DES model to investigate and characterize the epidemiology of diabetes during pregnancy and birth outcomes related to maternal …

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Improving Quality Of Service In Ems Systems By Reducing Disparities Between Service Zones, Sunarin Chanta Aug 2011

Improving Quality Of Service In Ems Systems By Reducing Disparities Between Service Zones, Sunarin Chanta

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Emergency medical service (EMS) systems respond to emergency or urgent calls so as to provide immediate care, such as pre-hospital care and/or transportation, to hospitals. Care must be provided in a timely manner; in fact quality of service is usually directly associated with response time. To reduce the response time, the number and location of vehicles within the service area are important variables. However with limited capacity, increasing the number of vehicles is often an infeasible alternative. Therefore, a critical design goal is to decide at which facilities stations should be located in order to serve as much demand as …

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Exploring Elementary School Teachers' Perception Of Their Role In Teaching Content Literacy In The Elementary, Lisa Jones-Moore Aug 2011

Exploring Elementary School Teachers' Perception Of Their Role In Teaching Content Literacy In The Elementary, Lisa Jones-Moore

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This mixed-methods study explored third, fourth, and fifth grade teachers' perceptions of their role in teaching content literacy in the elementary science and social studies classroom. The rationale for this study was the growing number of studies questioning the reliance on the inoculation theory for content area literacy comprehension. The study was a mixed methods study so as to provide insight into the participants' thought processes in decision making and instructional planning. Data sources included timed instructional observations, tiered checklist to identify strategy instruction, and prompted critical reflections. The three-tiered observation instrument categorized strategies used by teachers in tiers according …

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