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Crowe, Sarah Lynn. "Cardioprotective effects of dihydropyridine antagonists in a murine model of chronic iron-overload." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2002. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ65615.pdf.
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Yardimci, Ulaş Izmen. "Enough is as good as a feast : a simple model of choice overload." Master's thesis, Instituto Superior de Economia e Gestão, 2018. http://hdl.handle.net/10400.5/18013.
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Mestrado em EconomiaO pressuposto fundamental da teoria económica neoclássica é a racionalidade dos agentes econômicos. No entanto, no tempo, desvios sistemáticos desta suposição foram observados. Vários desses desvios dizem respeito ao processo de tomada de decisão e um deles é a carga aparentemente contraditória que se origina do número abundante de alternativas disponíveis. O comportamento sub-ótimo causado por esse fardo que é chamado de "sobrecarga de escolha" foi observado em experimentos de campo e de laboratório e posteriormente introduzido em alguns modelos econômicos modernos. Esta dissertação fornece um modelo simples para sobrecarga de escolha. Ao dividir o fenômeno em três partes, o fator de novidade, o custo de avaliar as escolhas e o pesar antecipado, examina os elementos que constituem a sobrecarga de escolha. Posteriormente, este trabalho fornece um exemplo do papel da sobrecarga no contexto do Dilema do Prisioneiro.
The fundamental assumption of neoclassical economic theory is the rationality of economic agents. Nonetheless, in time, systematic deviations from this assumption has been observed. A number of such deviations pertains to the decision-making process and one of them is the rather seemingly contradictory burden originating from the abounding number of alternatives available. Suboptimal behavior caused by this burden that is called "choice overload" has been observed in field and laboratory experiments and subsequently introduced into some modern economic models. This dissertation provides a simple model for choice overload. By breaking the phenomenon into three parts, the novelty factor, the cost of evaluation of choices, and the anticipated regret, it examines the elements that constitute choice overload. Subsequently, this work provides an example of the role choice overload may play in the context of Prisoner's Dilemma.
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Lunova, Mariia [Verfasser]. "Hepcidin knockout mice as a model of iron-overload associated liver disease / Mariia Lunova." Ulm : Universität Ulm. Medizinische Fakultät, 2013. http://d-nb.info/1045278475/34.
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Advani, Tushar M. "Brain derived neurotrophic factor deficient mouse a putative model of allostatic overload : a dissertation /." San Antonio : UTHSC, 2008. http://proquest.umi.com.libproxy.uthscsa.edu/pqdweb?did=1588771861&sid=7&Fmt=2&clientId=70986&RQT=309&VName=PQD.
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Johnson, Luke A. "Locus Coeruleus and Hippocampal Tyrosine Hydroxylase Levels in a Pressure-Overload Model of Heart Disease." Digital Commons @ East Tennessee State University, 2013. https://dc.etsu.edu/honors/288.
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Studies have indicated that approximately 30% of people with heart disease experience major depressive disorder (MDD). Despite strong clinical evidence of a link between the two diseases, the neurobiological processes involved in the relationship are poorly understood. A growing number of studies are revealing similar neuroanatomical and neurochemical abnormalities resulting from both depression and heart disease. The locus coeruleus (LC) is a group of neurons in the pons that synthesize and release norepinephrine, and that is known to play a significant role in depression pathobiology. For example, there is evidence that tyrosine hydroxylase (TH) is elevated in the LC in depression. In addition, there is evidence that the LC plays a role in cardiovascular autonomic regulation. The hippocampus is another region that exhibits abnormalities in both depression and heart disease. In this study, the levels of TH in the hippocampus and LC were examined in the guinea pig pressure-overload model of heart disease. TH levels were also measured in the pressure-overload model treated with vagal nerve stimulation, a new investigational therapeutic intervention in heart disease. This study found that there were no changes in TH levels in the LC or the hippocampus of the pressure-overload model or in the pressure-overload model treated with vagal nerve stimulation.
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Jordaan, Esaias Engelbertus. "Evaluation of isolated dorsal root ganglion cells as a model to study neural calcium overload / E.E. Jordaan." Thesis, North-West University, 2004. http://hdl.handle.net/10394/645.
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Background and motivation: The event of neural Ca2+ overload is known to have
several deleterious effects resulting in cell death caused by ischaemia, hypoglycaemia,
hypoxia and several neurodegenerative diseases such as Alzheimer's disease,
Parkinson's disease and AIDS-related dementia. In vitro models for the investigation
of the mechanisms involved in Ca2+ overload include brain slice preparations,
neuronal cultures as well as acutely isolated neurons, mostly from the hippocampus
and cortical brain areas. Additional models for investigating Ca2+ overload may bring
about new knowledge to areas of the phenomenon that are still unresolved.
Methodology: In this study, several theoretical Ca2+ overload-related interventions
were combined aimed at inducing cell death in acutely isolated rat dorsal root ganglia.
To elucidate the mechanism/s involved in the cell death observed following exposure
to this intervention, the effects of several alterations to the intervention's composition
were assessed. This examination was extended by the addition of several recognized
and potential protective compounds to the intervention. Cell death was indicated by
the trypan blue exclusion assay and recorded after 18 hours exposure to the
interventions by counting live and dead neurons under a light microscope.
Results and conclusions: The goal was to evaluate the possible application of dorsal
root ganglia as a model for neural Ca2+ overload outside the brain. Since Ca2+w as
required for cell death to be induced, it is concluded that the observed cell death was
indeed primarily due to Ca2+ overload. Besides extracellular Ca2+, KC1-induced
depolarization was also required for cell death to be induced, while the antagonists did
not demonstrate significant protection against cell death. Based on the results, the
mechanism of Ca2+ overload could not be defined beyond doubt, but the voltage activated
Ca2+ channels are likely to be involved.Thesis (M.Sc. (Physiology))--North-West University, Potchefstroom Campus, 2005.
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Schymura, Yves [Verfasser]. "Effects of Riociguat and Sildenafil in a murine model of chronic right ventricular pressure overload / Yves Schymura." Gießen : Universitätsbibliothek, 2013. http://d-nb.info/1065320558/34.
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Wolfberg, Adrian. "A Theory of Overload and Equivocality Effects on Learning during Knowledge Transfer within Policy Making Dyads." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1393843187.
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Pavlaki, Nikoleta [Verfasser]. "Gene therapy with phosphodiesterases 2A and 4B in a murine model of pressure overload-induced cardiac hypertrophy / Nikoleta Pavlaki." Hamburg : Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky, 2021. http://d-nb.info/1237050472/34.
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Allen, Adrian. "Modulation of contractile function through neuropeptide Y receptors during the development of cardiomyocyte hypertrophy in a model of pressure overload." Thesis, Queen's University Belfast, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368483.
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Tokola, H. (Heikki). "Mechanical stretch and peptide growth factors in the regulation of the hypertrophic response of cardiomyocytes:ANP and BNP as model genes." Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526210001.
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Abstract Cardiac hypertrophy is the primary adaptive mechanism of the heart to increased workload, though when advanced, it becomes a leading predictor for heart failure and sudden death. The growth stimulus elicited by a hemodynamic load is attributable to a combination of mechanical and neurohumoral factors, but the precise roles of individual growth promoting components are still unclear. This study utilized atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) as model genes with which to investigate the involvement and mechanisms of mechanical stress and peptide growth factors in hypertrophic response of cardiac myocytes. The direct effect of mechanical stretch was studied in two different in vitro models of cultured neonatal rat cardiomyocytes. In the first approach, hypo-osmotic swelling -induced stretch increased ANP mRNA levels in atrial cells. In the second model, cyclic mechanical stretch of ventricular cells grown on flexible membranes evoked ANP and BNP gene expression and secretion. The mechanisms of stretch-induced BNP gene expression were studied by measurement of the activities of transcription factors and by utilizing promoter analysis together with site specific mutations. Stretch activated the binding of the transcription factor GATA-4 similarly to pressure overload in vivo. Mutational studies revealed that specific GATA consensus sites on the BNP promoter, in combination with an Nkx-2.5 binding element, were critical for stretch-activated BNP transcription. Importantly, a reduction of GATA-4 protein levels inhibited the stretch-induced hypertrophic response. Both cyclic mechanical stretchin vitro and hemodynamic overload in vivo activated the expression of peptide growth factor bone morphogenetic protein-2 (BMP-2). The effects of BMP-2 closely resembled those of mechanical stretch including the increase in the expressions of ANP and BNP. Furthermore, the BMP antagonist noggin inhibited the effect of stretch on ANP and BNP. Fibroblast growth factor 1 stimulated ANP synthesis and secretion in a protein kinase C dependent manner. In conclusion, this work demonstrates that mechanical stretch per se is sufficient to activate the hypertrophic gene program in cardiac myocytes. This effect seems to be at least partially mediated by the growth factor BMP-2 acting in a paracrine manner. The activation of the GATA-4 transcription factor, in cooperation with a factor binding to the Nkx-2.5 binding element, is essential for mechanical stretch-induced cardiomyocyte hypertrophyTiivistelmä Sydämen tärkein mukautumiskeino kohonneeseen työmäärään on sydänlihaksen kasvu. Sydänlihaksen liikakasvu on kuitenkin tärkein sydämen vajaatoiminnan ja äkkikuoleman ennustetekijä. Hemodynaamisen ylikuormituksen kasvua edistävä vaikutus on lukuisten mekaanisten ja neurohumoraalisten tekijöiden summa, jossa kunkin yksittäisen tekijän osuus on vielä epäselvä. Tässä väitöskirjatyössä tutkittiin mekaanisen venytyksen ja peptidikasvutekijöiden osuutta ja vaikutusmekanismeja sydämen liikakasvun synnyssä käyttämällä malligeeneinä sydämen eteispeptidiä (ANP) ja B-tyypin natriureettista peptidiä (BNP). Mekaanisen venytyksen välitöntä vaikutusta tutkittiin vastasyntyneen rotan sydänsoluviljelymalleissa. Osmolaliteetin muutoksella aiheutettu venytys lisäsi ANP:n lähetti-RNA-tasoja eteissoluissa. Venyväpohjaisilla kalvoilla kasvatettujen kammiosolujen syklinen venytys stimuloi ANP:n ja BNP:n geeniekspressiota ja eritystä. BNP:n geenisäätelymekanismeja tutkittiin mittaamalla transkriptiotekijöiden aktiivisuutta sekä geeninsiirtokokeilla hyödyntäen muunneltuja BNP:n geenisäätelyalueita. Venytys lisäsi transkriptiotekijä GATA-4:n sitoutumisaktiivisuutta samaan tapaan kuin painekuormitus koe-eläimillä. Tietyt BNP:n säätelyalueen GATA-sitoutumispaikat yhdessä Nkx-2.5:ttä sitovan elementin kanssa osoittautuivat tärkeiksi venytysvasteen kannalta. GATA-4 -proteiinitasojen vähentäminen esti venytyksen aiheuttamaa kasvuvastetta. Sekä syklinen mekaaninen venytys soluviljelykokeissa että hemodynaaminen ylikuormitus koe-eläimillä lisäsivät peptidikasvutekijä bone morphogenetic protein-2:n (BMP-2) geeniekspressiota. BMP-2:n suorat vaikutukset puolestaan muistuttivat läheisesti mekaanisen venytyksen vaikutusta, ANP:n ja BNP:n lisääntynyt geeniekspressio mukaan lukien. BMP-antagonisti noggin esti lisäksi venytyksen vaikutusta ANP:iin ja BNP:iin. Työssä osoitettiin myös, että fibroblastikasvutekijä 1 stimuloi ANP:n synteesiä ja eritystä proteiinikinaasi C:n välityksellä. Yhteenvetona tulokset osoittavat, että mekaaninen venytys itsessään riittää aktivoimaan sydänlihaksen kasvuun liittyvää geeniohjelmaa. Vasteen välittäjänä näyttää kuitenkin ainakin osittain toimivan paikallisesti tuotettu BMP-2. Edelleen, transkriptiotekijä GATA-4 yhdessä Nkx-2.5 -elementtiin sitoutuvan tekijän kanssa osoittautui välttämättömäksi mekaanisen venytyksen aiheuttamalle kasvuvasteelle
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Hapuarachchi, John Romuald. "Work-home conflict as mediating the impact of role conflict and role overload on burnout and job satisfaction in psychiatric nurses : a test of 'partial medication spill-over' model /." Title page, contents and abstract only, 1995. http://web4.library.adelaide.edu.au/theses/09AR.PS/09ar.psh252.pdf.
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Petrarulo, Anna Chiara. "Il settore calzaturiero: studio di una linea di produzione del lusso made in Italy - il caso Baldinini s.r.l." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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Il settore calzaturiero si è affacciato di recente all’innovazione mantenendo una componente artigianale prevalente.
Lo studio ha evidenziato la necessità di intervenire sui processi produttivi per ridurre i costi di produzione e migliorare le capacità di risposta ai clienti. A seguito di una revisione della letteratura sui temi delle linee di assemblaggio e del bilanciamento, è stato studiato l’efficientamento della linea di produzione di calzature Baldinini. Mediante un’analisi tempi e metodi sono stati oggettivati i tempi di produzione della linea di assemblaggio mixed-model dell’azienda. A partire dai tempi rilevati, sono stati studiati un dimensionamento della linea in corrispondenza della produttività giornaliera attuale ed un dimensionamento per far fronte ad un incremento di produttività. In entrambi i casi è risultato necessario disporre di uno stesso numero di operatori di linea.
L' approccio alla gestione del work-overload time è stato duplice: il ricorso a manodopera jolly e/o l'assegnazione del lavoro eccedente ad operatori di linea con elevati idle time. Una distribuzione non equilibrata dei carichi di lavoro ha reso necessario uno studio del bilanciamento di tipo MALBP.
Il bilanciamento ha consentito di ridurre il numero di operatori di linea e di accrescere i loro tassi di utilizzo, mantenendo un numero di operatori jolly pari a quelli della linea non riconfigurata.
La riassegnazione dei carichi di lavoro è stata poi valutata nel caso di incremento della produzione ed è emerso un impatto sul work-overload time tale da rendere necessario un maggior numero di operatori jolly, a fronte di un numero complessivo di operatori comunque inferiore a quello necessario nel caso di linea non riconfigurata.
Ulteriori interventi di efficientamento, su stazioni di lavoro specifiche, hanno consentito di ridurre i tempi di esecuzione di alcune operazioni aprendo per l'azienda la strada ad un processo di miglioramento continuo e di riconversione tecnologica.
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Leitzinger, Christin [Verfasser], Jerzy [Akademischer Betreuer] Adamski, Jerzy [Gutachter] Adamski, and Martin [Gutachter] Klingenspor. "Mitochondrial copper overload in a rat model for Wilson disease is paralleled by upregulated COX17 and can be restored using the bacterial peptide methanobactin / Christin Leitzinger ; Gutachter: Jerzy Adamski, Martin Klingenspor ; Betreuer: Jerzy Adamski." München : Universitätsbibliothek der TU München, 2017. http://d-nb.info/1181326087/34.
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Mohin, Ma. "Fatigue crack growth assessment and fatigue resistance enhancement of aluminium alloys." Thesis, University of Hertfordshire, 2018. http://hdl.handle.net/2299/20824.
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Fatigue damage of aluminium alloys is one of the key concerns in transport industries, particularly in the aerospace industry. The purpose of the project is to develop new knowledge and techniques against fatigue failure for these industries through a systematic investigation of fatigue resistance and crack growth behaviours of aluminium alloys. Fatigue and fracture mechanics have been investigated analytically, numerically and experimentally in this project. Overload transient effect on fatigue crack growth has been examined by considering various parameters including crack closure, overload ratio (OLR), load ratio (R ratio), baseline stress intensity factor range, (∆K)_BL and geometry. It was found that crack closure can be correlated qualitatively and quantitatively to all other parameters associated with overload transient behaviour. It is proposed that the effect of crack tip plasticity on the non-linearity of the compliance curve can be separated to obtain reliable crack closure measurement. In this project, different methods are used to better understand the transient retardation process so that the damage tolerance design (DTD) of the components made of aluminium alloys can be enhanced. Another important parameter for fatigue and damage tolerance design (DTD) of engineering components is the threshold stress intensity factor range for fatigue crack growth, ∆K_th. A small variation in identification of ∆K_th can lead to a big change in overall estimation of fatigue life. In this project, an analytical model has been developed for aluminium alloys by fitting an analytical curve with raw crack growth data in order to identify the ∆K_th. This model has the capacity to identify ∆K_th for different aluminium alloys at various R ratios. There is a great demand for enhanced fatigue life of aluminium alloys in the transport industry. This project has carried out a detailed investigation of electromagnetic treatment (ET) in the form of electropulsing treatment to develop an efficient technique for fatigue resistance enhancement. ET parameters including the treatment intensity, treatment time and the number of applications have been optimised. It is suggested that the duration of ET treatment can be used as the main parameter among all these to control the fatigue resistance of the aluminium alloy. The improvement in fatigue resistance has been explained by the change in microhardness and conductivity of aluminium alloy due to ET. Additionally, the fracture morphology was analysed using scanning electron microscopy (SEM). The precipitates and dislocation characteristics were also studied using transmission electron microscopy (TEM). The outcomes of this investigation will help improve structural integrity by enhancing fatigue resistance of aluminium alloys.
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Pathan, A. H. "Some overload control models for processor controlled systems." Thesis, University of Strathclyde, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382442.
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NASCIMENTO, EDSON. "OVERLOAD CORRECTIVE CONTROL CALCULATIONS: ALGEBRAIC ASPECTS OF LINEAR MODELS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1985. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=14022@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
UNIVERSIDADE FEDERAL DO MARANHÃO
Quando um sistema elétrico de potência é levado a operar no estado de emergência, em tempo real de operação, o principal objetivo do centro de controle é calcular controles corretivos com a finalidade de levá-lo à região normal o mais rápido possível. A maioria das vezes, em tal situação, deve ser necessário calcular e implementar ações de controle, tais como redespacho de geração de potência ativa e reativa para eliminar as restrições de operação violadas, conservando as restrições de carga satisfeitas. Esta pesquisa foi desenvolvida tendo como objetivo: a) a revisão crítica de alguns algoritmos que usam formulações lineares conhecidos até o momento, para calcular controles corretivos; b) a elaboração de uma modelagem matemática deste problema; c) a análise dos aspectros algébricos das formulações lineares e suas conseqüências na obtenção da solução; d) a proposição de uma formulação mais completa e concisa. Vários métodos são apresentados e aplicados em um sistema de pequena dimensão.
When an electrical power system gets into na emergency state during its real time operation the main objective of the control center is to calculate corrective controls in order to put the system back in the normal region as fast as possible. Almost every time, in such a situation, it ought to be necessary to calculate and implement corrective actions, such as real and reactive constraints, while keeping the load constraints satisfied. This research was developed having as objectives: a) the critical review of many of the algorithms using linear formulations know up to now for calculating corrective controls; b) the elaboration of a mathematical model of this problem; c) the analysis of algebraic aspects of the linear formulations and theirs consequences on the solution; d) the proposition of a more complete and concise formulation. Several methods are presented and applied to a small size system
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Fang, Po-Hsuan. "Customer confusion: product overlap, ambiguous needs, and information overload : an examination of corporate mental models for derivative product creation and their impact on customers." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122243.
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Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2019Cataloged from PDF version of thesis.
Includes bibliographical references (pages 49-50).
Companies in highly competitive industries often develop incremental products to meet diverse customer needs or to gain share from competitors. However, in order to help customers to choose between derivatives, companies also present more detailed product specifications or features to their customers, resulting in customer confusion. We categorized customer confusion into three facets: product overlap, ambiguous needs, and information overload and discussed each confusion in three case studies. This thesis presents a theory of mental models for companies facing this issue, and uses three case studies to examine the issue : Groceries (Trader Joes), Wearable Devices (Fitbit), and Semiconductor (Texas Instruments). We conclude that product ambiguity is the dominant type of customer confusion in the grocery retail industry. Trader Joe's has adopted the no sale strategy to mitigate this effect. We identify information overload as the most significant concern in wearable devices from the Fitbit case, where online user reviews supplement specification information. Finally, we find that contextual ambiguity is a huge problem for the customers in the semiconductor industry. Several strategies such as customer support and enhanced web content are identified to reduce this ambiguity. We propose three system diagrams showing how company strategies affect customer confusion regarding different levels of product knowledge and ability to acquire new knowledge. The diagrams shed light on how sales support could intervene effectively, based on the customer type and confusion type.
by Po-Hsuan Fang.
S.M. in Engineering and Management
S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program
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Junkert, Levi Daniel. "The grid overlay system model." Thesis, Montana State University, 2009. http://etd.lib.montana.edu/etd/2009/junkert/JunkertL0509.pdf.
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The grid overlay system model is a new technique for forming a grid computing model for research computing. In this method we construct a grid that is dynamically allocated from a set of resources in a unique and progressive manner. This new system model allows for construction of virtual environments for execution of applications on many diverse shared resources. The system can dynamically scale to create a range of resources from a single machine to a virtual cluster of machines. This model provides a virtual container that can run legacy and customized software in an emulated environment or directly on the host's hardware through virtualization. Using this model on current consumer hardware allows for a unique blend of software containment with dynamic resource allocation. Our model, in combination with commercial off the shelf (COTS) hardware and software, is able to create a large grid system with multiple combinations of hardware and software environments. In our model we propose a unique set of abstraction layers for systems. The combination of our model with current consumer hardware and software provides a unique design principle for addressing grid implementation, hardware reusability, operating system deployment and implementation, virtualization in the grid, and user control techniques. This provides a robust and simple framework that allows for the construction of computational research solutions in which performance can be traded for flexibility, and vice versa. Our model can be applied to computational research grids, service oriented grids, and even scales to collections of mobile or embedded system grids.
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Aroui, Karim. "Séquencement d’une ligne de montage multi-modèles : application à l’industrie du véhicule industriel." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAI029/document.
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Dans cette thèse, nous considérons le problème du séquencement sur une ligne de montage multi-modèles de véhicules industriels. Pour équilibrer au mieux la charge dynamique des opérateurs, la minimisation de la somme des retards à l’issue de chaque véhicule est proposée.Deux approches peuvent être utilisées pour optimiser le lissage de charge dans un problème de séquencement : l’utilisation directe des temps opératoires ou le respect de règles. La plupart des travaux appliqués à l’industrie automobile utilisent l’approche de respect de règles. Une originalité de ce travail est d’utiliser l’approche de la prise en compte directe des temps opératoires.L’étude de la littérature de ce problème a dévoilé deux lacunes dans les travaux précédents : l’essentiel des travaux modélisent un seul type d’opérateurs d’une part, et proposent des heuristiques ou des métaheuristiques pour résoudre ces problèmes, d’autre part. L’originalité de ce travail est de tester des méthodes exactes pour des instances industrielles et de modéliser le fonctionnement de trois différents types d’opérateurs spécifiques au cas industriel.Deux méthodes exactes sont développées : la programmation linéaire mixte et la programmation dynamique. Une étude expérimentale des facteurs de complexité sur des instances académiques des deux modèles est développée. Les modèles sont aussi testés sur des instances du cas d’étude.Par ailleurs, le problème est traité par deux méthodes approchées : une heuristique basée sur la programmation dynamique d’une part, et des métaheuristiques (algorithme génétique, recuit simulé et un couplage des deux) d’autre part. Les deux approches sont testées sur des instances académiques et des instances du cas d’étude.Ce travail a permis d’apporter une solution intéressante d’un point de vue industriel puisqu’il prend en compte les caractéristiques de la ligne de montage (opérateurs spécifiques) et améliore significativement la qualité du séquencement en un temps de calcul raisonnableIn this thesis, the problem of sequencing mixed model assembly lines (MMAL) is considered. Our goal is to determine the sequence of products to minimize the work overload. This problem is known as the mixed model assembly line sequencing problem with work overload minimization (MMSP-W). This work is based on an industrial case study of a truck assembly line.Two approaches can be used to minimize the work overload: the use of task operation times or the respect of sequencing rules. Most of the earlier works applied in car industry use the latter approach. The originality of this work is to employ the task operation times for the generation of the product sequence in a MMAL.The literature review has highlighted two main gaps in previous works: most of the papers consider a single type of operators, and propose heuristics or metaheuristics to solve the problem. The originality of this work is to test exact methods for industrial case instances and to model three different types of operators.Two exact methods are developed: the mixed integer linear programming and dynamic programming. The models are tested on industrial case study instances. An experimental study is developed for both approaches in order to understand the complexity factors.Moreover, the problem is treated by two approximate methods: a heuristic based on dynamic programming and metaheuristics (genetic algorithm, simulated annealing and a hybrid method based on both genetic algorithm and simulated annealing). All approaches are tested on academic instances and on real data from the industrial case study
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Parkar, M. A. "Overland flow in urban catchments." Thesis, Nottingham Trent University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376095.
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A three parameter pseudo-linear reservoir model was developed and tested using data collected from urban catchments in Nottingham. Some 550 individual rainfall-runoff events, from ten different catchments, were recorded (from May 1983 to June 1985) and available for analysis. parameters, depression storage and runoff an effective hyetograph to be obtained from the The third parameter, KATCH, was a catchment obtained by an optimisation technique applied to Two- of the model coefficient, enabled measured hyetograph. constant which was development data sets. The rainfall loss parameters were determined using both the traditional method of linear regression analysis of rainfall-runoff depths, and by model optimisation of development data sets. Two versions of the pseudo-linear reservoir model were tested and results from both versions were compared with the results from the non-linear reservoir model, which is the overland flow routing model currently used in the Wallingford Procedure for the design and analysis of urban storm drainage in the United Kingdom. When the overall goodness-of-fit between simulated and observed hydrographs was assessed (using the Biassed Integral Square Error, BISE), similar model performance results were obtained for both versions of the pseudo-linear reservoir model and the non-linear reservoir model applied to paved surfaces. The pseudo-linear reservoir model accounted for the routing of flows, both on the surface and through the secondary drainage system, via the catchment constant, KATCH. For the two sub-catchments with secondary drains, the non-linear reservoir model over-estimated peak flows by some 401, since the model ignores routing through the drains. The pseudo-linear reservoir model gave consistently better results when compared with the non-linear reservoir model for storms monitored from an uncalibrated sub-catchment of mixed roof and paved surfaces. (
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Clum, Craig M. "Highway traffic noise barrier overlap gap model." Ohio : Ohio University, 1997. http://www.ohiolink.edu/etd/view.cgi?ohiou1177442958.
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Ferrara, Riccardo. "A Numerical Model to Predict Train Induced Vibrations and Dynamic Overloads." Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2013. http://tel.archives-ouvertes.fr/tel-00842993.
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A numerical model to predict train induced vibrations is presented. The dynamic computation considers mutual interactions in vehicle/track coupled system by means of a finite and discrete elements method. The vehicle is modeled by 7 bi-dimensional rigid elements representing: the body, the two boogies and the four wheels. The railway is discretized as finite Timoshenko beam elements. Axial deformation is assumed insignificant. The substructure is made-up of: rail-pads, sleepers, ballast, and background. Rail-pads are modeled as spring/damper couples without mass and sleepers are modeled as rigid elements. The rail-sleeper contact is assumed extended to a connection-area, rather than a single point assumption. To model this area many spring/damper couples are disposed along the length of sleepers. The ballast is modeled as blocks of mass made-up of rigid elements, connected to sleeper by spring/damper couples. To allow the transmission of vibrations in longitudinal direction too, spring/damper couples connect ballast elements horizontally.The dynamic interaction between the wheel-sets and the rail is accomplished by using the non-linear Hertzian model with hysteresis damping. The rail defects and the case of out-of-round wheels are considered too.A modal analysis of supporting structure is done to validate the substructure model comparing it to experimental data.Comparisons between numerical results of our model, experimental data and numerical results of others literature models are done on contact-force, rail accelerations and sleepers accelerations to validate the coupled vehicle/track system.Moreover a modal analysis of the coupled vehicle/track system is done to analyze the relationship between resonance frequencies, train velocities and ballast displacements.A sensitivity analysis is done to evaluate the variables more affecting the maintenance costs. The parameters more conditioning the ballast maintenance costs are the ballast modulus and the train mass.The effects of train velocity on the ballast displacements are analyzed in relationship with substructure properties. A new formulation to evaluate the railway toll connected to ballast wear is introduced.A new interpretation of the critical velocity in the range 100-300 km/h is proposed.
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Fruchon, Séverine. "Modulation de la surcharge en fer dans un modèle murin d'hémochromatose : mise en évidence de facteurs génétiques et études d'expression génique." Toulouse 3, 2004. http://www.theses.fr/2004TOU30274.
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L'hémochromatose génétique de type 1 est caractérisée par une surcharge en fer dans les organes parenchymateux. Elle est provoquée par une mutation ponctuelle (C282Y) du gène HFE, très fréquente dans les populations originaires du nord ouest de l'Europe. Des études épidémiologiques récentes mettent en évidence une pénétrance incomplète et une variabilité de l'expressivité de la maladie. Ceci peut s'expliquer par l'action de facteurs non génétiques (âge, alimentation, dons de sang réguliers. . . ) et génétiques. Pour étudier l'action de ces derniers dans l'intensité de la surcharge hépatique, nous avons utilisé un modèle murin d'hémochromatose : les souris Hfe-/-. L'étude comparative de 4 souches de souris consanguines (C57BL/6, CBA, DBA/2 et 129/Sv) a montré des différences de régulation du métabolisme du fer selon les souches. L'analyse de souris Hfe-/- sous deux fonds génétiques distincts (C57BL/6 et DBA/2) a révélé que l'intensité de la surcharge en fer varie en fonction de la souche et fait intervenir d'autres gènes qui modulent l'action de HFE. Nous avons démontré que les souris Hfe-/- des deux fonds génétiques varient, non seulement par l'intensité de la surcharge mais aussi par les régulations transcriptionnelles mises en jeu dans le duodénum. Par une approche de criblage du génome, nous avons identifié quatre régions chromosomiques avec un lod score significatif d'une liaison génétique. Enfin, le niveau hépatique d'expression des ARNm de diverses molécules dont l'hepcidine a été dosé chez des souris Hfe-/- de deux souches (C57BL/6 et DBA/2). Bien que nous n'ayons pas mis en évidence de différence significative de l'expression de l'ARNm de l'hepcidine 1 entre les souris Hfe+/+ et Hfe-/-, nos résultats révèlent que l'expression des ARNm de l'hepcidine 1 et 2 varie selon la souche de sourisType 1 genetic hemochromatosis is characterised by an iron overload in parenchyme organs. A mutation (C282Y) in the HFE gene is the cause of the disease which is very frequent in the populations of North West Europe origins. Recent epidemiological studies revealed an incomplete penetrance and a variable expression of the disease. Involvement of non genetic factors (age, nutrition, regular blood donations. . . ) and of genetic factors can explain this picture. To characterise the role of the genetic factors in hepatic iron loading, we have used the Hfe-/- mouse as a murine model of hereditary hemochromatosis. The comparative study of 4 consanguineous mouse strains (DBA/2, C57BL/6, CBA and 129/Sv) showed differences in the regulation of iron metabolism between strains. Hfe-/- mice with two different genetic backgrounds (C57BL/6 and DBA/2) showed differences on iron overload levels which are controlled by other genes modulating HFE gene. We showed that in these two Hfe-/- strains, the iron overload levels and the transcriptional regulations in duodenum are different. Screening the whole genome, four chromosomic regions with a significant LOD score of genetic linkage were identified. The mRNA expression was quantified for hepcidin and other molecules among the two strains of Hfe-/- mice. Though there was no significant differences in hepcidin 1 mRNA levels between the Hfe-/- and Hfe+/+ mice, our results showed that there was higher mRNA expression for hepcidin 1 than for hepcidin 2 in C57BL/6 mice and the opposite was observed in DBA/2 mice
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Lopez, Sabater Carlos Joaquin. "An empirical model of hydraulic roughness for overland flow." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/280353.
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This research has developed a method for estimating hydraulic roughness coefficients for overland flow models in a dynamic approach, to more effectively simulate runoff on natural, agricultural and urban slopes. The hydraulic roughness coefficients are then generated with a series of neural networks. First, a laboratory experiment was designed to explore the effects of soil microtopography, slope and Reynolds number on the magnitude of Darcy-Weisbach, Manning and Chezy roughness coefficients. It was found that three parameters were necessary to describe the soil surface microtopography. Neural networks developed in a preliminary phase were able to reproduce the roughness coefficients obtained in the laboratory experiment by using five predictor variables: bed slope, Reynolds number, and the three parameters used to describe the microtopography. However, these networks failed to generate roughness coefficients for different input variables (generalization). Second, more complex algorithms were developed as combinations of neural networks in parallel. The algorithm output, the sought hydraulic roughness estimate, was estimated with the arithmetic average of the individual network outputs. Results presented in this study demonstrate that combining multiple neural networks reduced the prediction error and improved on the generalization ability of the neural networks. It was also observed that the estimate accuracy was influenced by the characteristics of the dataset, and especially by the relationship between the roughness coefficient and Reynolds numbers. Finally, a field experiment was performed to explore the applicability of the algorithms. A numerical model based on the 1-D diffusion approximation to the Saint Venant equations was constructed, and two surface irrigations were performed to collect data to test the model estimates. The model was used under two scenarios: (1) with constant hydraulic roughness coefficients, and (2) using variable hydraulic roughness predicted with the algorithm. Discharge at the end of the plot and irrigation front advance estimated using both models matched the observations well. However, when using a variable hydraulic roughness, the front was initially delayed until there was a sufficient surface storage to push it forward. The methodology described in this research should be useful for 2-D overland flow models applied to natural slopes with unsteady rainfall.
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MULLER, NELSON. "OVERLOAD CORRECTIVE CONTROL CALCULATION BY FIRST AND SECOND ORDER MODELS IN RETANGULAR COORDINATES." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1985. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=14018@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORO aumento da complexidade dos sistemas elétricos de potência tem feito crescer o interesse pela operação e controle em tempo real. Tornou-se então necessária, a criação de centros de controle e computadorizados cujo objetivo principal é suprir toda a carga com todas as restrições de operação satisfeitas e a custo mínimo. Evidencia-se assim, a necessidade de desenvolvimento de algoritmos para o controle corretivo da operação em tempo real, como por exemplo para o controle corretivo de sobrecargas. Os algoritmos existentes têm utilizado como modelo as equações não-lineares de potência injetada nodal na forma polar. Estas equações, quando escritas na forma retangular, são quadráticas e apenas os três primeiros termos da expansão em série de Taylor são não-nulos. Desta forma, é possível que o termo da 1ºordem da expansão na forma retangular seja mais representativo das equações não-lineares que o termo da 1ª ordem na forma polar. Isto pode acarretar melhoras na característica de convergência do método de Newton-Raphson. Além disso, é possível utilizar um método de solução de equações quadráticas onde todos os três termos da expansão em série de Taylor são tomados em consideração. Nesta dissertação são desenvolvidos algoritmos de 1ª e 2ª ordens na forma retangular para o controle corretivo de sobrecargas em tempo real. A melhor maneira de se considerar as restrições nas variáveis de controle é mostrada. Os algoritmos utilizam análise de sensibilidade entre as diversas variáveis do sistema e, na busca da melhor formulação, diversos testes com vários sistemas foram efetuados. Os resultados são comparados entre si e com aqueles obtidos com as equações na forma polar.
The increase in complexity of the electrical power systems have risen the interest on real-time operation and control. The built of computarized control centers whose main objective is to supply the loads, with all the operation constratints satisfied at lowest cost, became necessary. Therefore, the development of real-time algorithms for secure and economic operation, as for instance for overload corrective control, turned out to be a consequence. The non-linear injected nodal power equations have been written in polar form in the existing algorithms. In rectangular form in the existing algorithms. In rectangular form, these equations are quadratic and their Taylor series expansion have only the first three terms. Hence, the first order term of the expansion in rectangular form might be more representative of the non-linear equations than the first order term in polar form. This may improve the converge characteristic of the Newton-Raphson method. Moreover, a quadratic equation solution method can be used. In this method, all the three terms of the Taylor series expansion are taken into account. In the dissertation 1st and 2nd orde algorithms in rectangular form for real-time overload corrective control are developed. The best way to deal with constraints on the control variables is pointed out. The algorithms use sensitivity analysis among the many system variables and, searching for the best formulation, the results using several test-systems are compared with each other and with those obtained with the equations in polar form.
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Ke, LinLin. "Design of a Forensic Overlay Model for Application Development." Thesis, University of Canterbury. Computer Science and Software Engineering, 2011. http://hdl.handle.net/10092/5479.
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Forensics capability is becoming increasingly important for the enterprise/network environment. Therefore, businesses need to find an optimised forensics solution that suits the high level business/forensics requirements. However, most businesses are still staying with the conventional method of digital investigation, which means using forensics tools to retrieve evidential data from the target system. Many businesses lack a comprehensive model to help understand the forensics requirements on different levels. Also, businesses lack a method to integrate and manage forensics knowledge into daily operation.
In this research, a forensics overlay is being developed on an existing business framework – SABSA model. The overlay helps different business roles to understand and apply forensics knowledge into their daily tasks. With help of the overlay, businesses are able to reduce the overreliance on the third party forensics tools through developing their own forensically sound applications. To test the theory of forensically sound application development, and evaluate the usability of the overlay, a forensically sound email client is designed and developed accordingly.
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Adolfsson, Fredrik. "A Model-Based Approach to Hands Overlay for Augmented Reality." Thesis, Linköpings universitet, Programvara och system, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-175190.
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Augmented Reality is a technology where the user sees the environment mixed with a virtual reality containing things such as text, animations, pictures, and videos. Remote guidance is a sub-field of Augmented Reality where guidance is given remotely to identify and solve problems without being there in person. Using hands overlay, the guide can use his or her hand to point and show gestures in real-time. To do this one needs to track the hands and create a video stream that represents them. The video stream of the hands is then overlaid on top of the video from the individual getting help. A solution currently used in the industry is to use image segmentation, which is done by segmenting an image to foreground and background to decide what to include. This requires distinct differences between the pixels that should be included and the ones that should be discarded to work correctly. This thesis instead investigates a model-based approach to hand tracking, where one tracks points of interest on the hands to build a 3D model of them. A model-based solution is based on sensor data, meaning that it would not have the limitations that image segmentation has. A prototype is developed and integrated into the existing solution. The hand modeling is done in a Unity application and then transferred into the existing application. The results show that there is a clear but not too significant overhead, so it can run on a normal computer. The prototype works as a proof of concept and shows the potential of a model-based approach.
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Cardoso, Elsa Maria Pereira. "Lymphocytes in the liver and hepatic iron toxicity : human and animal models of iron overload." Tese, Porto : Edição do Autor, 2000. http://catalogo.up.pt/F?func=find-b&local_base=UPB01&find_code=SYS&request=000087509.
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Cardoso, Elsa Maria Pereira. "Lymphocytes in the liver and hepatic iron toxicity : human and animal models of iron overload." Doctoral thesis, Porto : Edição do Autor, 2000. http://hdl.handle.net/10216/64561.
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Zhong, Yiming. "Modelling sediment transportation and overland flow." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:a45eefae-5a0f-4917-9abb-261ae792f2ee.
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The erosion and transport of fertile topsoil is a serious problem in the U.S., Australia, China and throughout Europe. It results in extensive environmental damage, reduces soil fertility and productivity, and causes significant environmental loss. It is as big a threat to the future sustainability of global populations as climate change, but receives far less attention. With both chemicals (fertilizers, pesticides, herbicides) and biological pathogens (bacteria, viruses) preferentially sorbing to silt and clay sized soil particles, estimating contaminant fluxes in eroded soil also requires predicting the transported soils particle size distribution. The Hairsine-Rose (HR) erosion model is considered in this thesis as it is one of the very few that is specifically designed to incorporate the effect of particle size distribution, and differentiates between non-cohesive previously eroded soil compared with cohesive un-eroded soil. This thesis develops a new extended erosion model that couples the HR approach with the one-dimensional St Venant equations, and an Exner bed evolution equation to allow for feedback effects from changes in the local bed slope on surface hydraulics and erosion rates to be included. The resulting system of 2I +3 (where I = number of particle size classes) nonlinear hyperbolic partial differential equations is then solved numerically using a Liska-Wendroff predictor corrector finite difference scheme. Approximate analytical solutions and series expansions are derived to overcome singularities in the numerical solutions arising from either boundary or initial conditions corresponding to a zero flow depth. Three separate practical applications of the extended HR model are then considered in this thesis, (i) flow through vegetative buffer strips, (ii) modelling discharge hysteresis loops and (iii) the growth of antidunes, transportational cyclic steps and travelling wave solutions. It is shown by comparison against published experimental flume data that predictions from the extended model are able to closely match measurements of deposited sediment distribution both upstream and within the vegetative buffer strip. The experiments were conducted with supercritical inflow to the flume which due to the increased drag from the vegetative strip, resulted in a hydraulic jump just upstream of the vegetation. As suspended sediment deposited at the jump, this resulted in the jump slowly migrating upstream. The numerical solutions were also able to predict the position and hydraulic jump and the flow depth throughout the flume, including within the vegetative strip, very well. In the second application, it is found that the extended HR model is the first one that can produce all known types of measured hysteresis loops in sediment discharge outlet data. Five main loop types occur (a) clockwise, (b) counter-clockwise, (c,d) figure 8 of both flow orientations and (e) single curve. It is clearly shown that complicated temporal rainfall patterns or bed geometry are not required to developed complicated hysteresis loops, but it is the spatial distribution of previously eroded sediment that remains for the start of a new erosion event, which primarily governs the form of the hysteresis loop. The role of the evolution of the sediment distribution in the deposited layer therefore controls loop shape and behavior. Erosion models that are based solely on suspended sediment are therefore unable to reproduce these hysteretic loops without a priori imposing a hysteretic relationship on the parameterisations of the erosion source terms. The rather surprising result that the loop shape is also dominated by the suspended concentration of the smallest particle size is shown and discussed. In the third application, a linear stability analysis shows that instabilities, antidunes, will grow and propagate upstream under supercritical flow conditions. Numerical simulations are carried out that confirm the stability analysis and show the development and movement of antidunes. For various initial parameter configurations a series of travelling antidunes, or transportational cyclic steps, separated by hydraulic jumps are shown to develop and evolve to a steady form and wave speed. Two different forms arise whereby (a) the deposited layer completely shields the underlying original cohesive soil so that the cohesive layer plays no role in the speed or shape of the wave profile or (b) the cohesive soil is exposed along the back of the wave such that both the non-cohesive and cohesive layers affect the wave profile. Under (a) the solutions are obtained up to an additive constant as the actual location of the boundary of the cohesive soil is not required, whereas for (b) this constant must be determined in order to find the location on the antidune from where the cohesive soil becomes accessible. For single size class soils the leading order travelling wave equations are fairly straightforward to obtain for both cases (a) and (b). However for multi-size class soils, this becomes much more demanding as up to 2I + 3 parameters must be found iteratively to define the solution as each size class has its own wave profile in suspension and in the antidune.
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Lu, Yihong C. S. "In vitro models of cartilage degradation following joint injury : mechanical overload, inflammatory cytokines and therapeutic approaches." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61238.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biological Engineering, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references.
Osteoarthritis (OA) is the most common form of joint disorder. Individuals who have sustained an acute traumatic joint injury are at greater risk for the development of OA. The mechanisms by which injury causes cartilage degradation are not fully understood, but the elevated levels of injury-induced pro-inflammatory cytokines, such as TNFa and IL-6, have been implicated to play important roles in the pathogenesis of OA. We have used in vitro models of cartilage injury to examine the interplay between mechanical and cytokine-mediated pathways and to identify processes associated with cartilage degradation following joint injury. The overall aims of this thesis were to characterize the combined effect of TNFa and IL-6/sIL6R on matrix degradation and chondrocyte gene expression in mechanically injured cartilage, and to investigate whether cartilage degradation could be inhibited by potential therapeutic approaches. TNFa and IL-6/sIL-6R interacted to cause aggrecanase-mediated proteoglycan degradation. Importantly, the combined catabolic effects of cytokines were highly potentiated by mechanical injury. Furthermore, cartilage degradation caused by the in vitro injury model appeared to be initiated at the transcriptional level, since the gene expression of matrix proteases, cytokines and iNOS were all highly elevated in the treatment conditions. The degradative effects of TNFa in injured cartilage was due, in part, to the action of endogenous IL-6, as proteoglycan degradation was partly reduced by an IL-6 blocking Fab fragment. Interestingly, cartilage degradation induced by the combinations of proinflammatory cytokines and mechanical injury was fully abrogated by short-term treatments with dexamethasone. The results of this work are significant in that they provide evidence suggesting joint injury affects cell-mediated responses as well as the transport of cytokines and proteases in extracellular matrix, making cartilage tissue more susceptible to further degradation by biochemical mediators.
by Yihong C.S. Lu.
Ph.D.
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Thoms, R. Brad. "Simulating fully coupled overland and variably saturated subsurface flow using MODFLOW /." Full text open access at:, 2003. http://content.ohsu.edu/u?/etd,16.
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Modala, Naga Raghuveer. "Methods to integrate overland, ephemeral gully and streambank erosion models." Kansas State University, 2010. http://hdl.handle.net/2097/7049.
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Master of ScienceDepartment of Biological & Agricultural Engineering
Kyle R. Douglas-Mankin
Sediment is considered as one of the important pollutant of concern in the U.S. In order to develop watershed management plans that address sediment pollution, it is essential to identify all sources of sediment in a watershed. The overall goal of this research is to quantify the total sediment from a watershed by integrating the outputs of three types of sediment sources: sheet and rill erosion, ephemeral gully erosion, and streambank erosion, that each operates at different spatial and temporal scales. This approach will be demonstrated in Black Vermillion River Watershed using AnnAGNPS (overland flow/erosion model), REGEM (ephemeral gully erosion model) and field measured values of streambank erosion. The study area includes three subwatersheds (Irish Creek, the Black Vermillion River Main Stem, and North Fork of the Black Vermillion), each monitored for continuous stream flow, base flow and event-based suspended sediment subwatershed export, annual streambank erosion, for 2 years. NASS land use, SSURGO soils data, 30-m DEMs, and local weather data were used to generate input data needed by the models. Stream monitoring data were used to calibrate the models. This paper will present results from independently calibrated and validated combinations of AnnAGNPS, REGEM, and filed measured streambank erosion. Our hypothesis is that use of separate models to simulate sediment load contributions for each sediment source will improve model agreement with measured watershed sediment yield data.
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Parsons, J. S. "A simulation model for subsurface and overland flow down a hillside in the Crimple Beck, N. Yorkshire." Thesis, University of Leeds, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376984.
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Gonçalves, Daniel Moreira. "Mechanisms underlying cardioprotection induced by exercise training in animal models of acute and chronic cardiac pressure overload." Tese, Faculdade de Desporto da Universidade do Porto, 2011. http://hdl.handle.net/10216/63666.
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Gonçalves, Daniel Moreira. "Mechanisms underlying cardioprotection induced by exercise training in animal models of acute and chronic cardiac pressure overload." Doctoral thesis, Faculdade de Desporto da Universidade do Porto, 2011. http://hdl.handle.net/10216/63666.
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Mast, Kimberly. "Multimedia in E-Learning." The University of Arizona, 2015. http://hdl.handle.net/10150/556151.
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Multimedia in E-Learnign and Cognitive OverloadMultimedia has infused itself into all aspects of education be it online, distance or in the face-to-face classroom. Its presence has become ubiquitous in education and yet has it really benefitted students to the degree it could? This paper utilizes a review of the literature to define the role of multimedia in e-learning then looks at how multimedia fits into basic pedagogy, learning theory and learning styles. An examination of how multimedia optimally could be incorporated into the curriculum is also conducted. Finally a look at cognitive overload is undertaken to determine if there is such as thing as too much of a good thing; can instructors end up confusing students with poorly designed multimedia presentations? There are many tools to use to present multimedia lessons however, this does not mean they all need to be used in a single lesson, and selecting the right multimedia tool, and content is imperative to ensure learning goals are met. Careful selection and attention to instructional design remains the key determinant in successful learning models and the incorporation of multimedia should be used with basic instructional pedagogy in mind.
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Benson, Victoria Louise St Vincent's Clinical School UNSW. "The role of calcineurin in high-renin and low-renin animal models of pressure overload left ventricular hypertrophy." Awarded by:University of New South Wales. St Vincent's Clinical School, 2005. http://handle.unsw.edu.au/1959.4/20843.
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Left ventricular hypertrophy (LVH) in response to pressure overload is associated with increased cardiovascular morbidity and mortality, making its prevention an important therapeutic goal. The role of a calcineurin-dependent molecular pathway in the induction of pressure-overload LVH is controversial. The present study tested the hypothesis that, in the setting of LV pressure overload, activation of the systemic renin-angiotensin system was necessary for activation of this calcineurin pathway. Mild LV pressure overload was induced in male Wistar rats by abdominal aortic constriction (AAC) or transverse aortic arch constriction (TAC), producing well-matched pressure gradients of 37 ?? 8 and 35 ?? 15 mmHg, respectively. Tight transverse aortic arch constriction (TTAC) in additional animals produced a pressure gradient of 75 ?? 15 mmHg. Only AAC increased plasma renin concentration and activated the calcineurin pathway, indicated by increased nuclear NFAT3 content. Plasma renin concentration and nuclear NFAT3 content were unchanged in TAC and TTAC animals. AAC animals developed more LVH 21 days post-banding than TAC and TTAC animals: the slope of the relationship between LV/body weight ratio and systolic blood pressure was much steeper in AAC animals than the combined TAC and TTAC animals (20x10-6 versus 5x10-6, p<0.001). Treatment with the calcineurin inhibitor FK506 did not significantly alter the slope of this relationship in the combined TAC and TTAC animals (8x10-6), but FK506 abolished this relationship in AAC animals (-5x10-6, R =0.0003). These data indicate that activation of the calcineurin pathway occurs only in high-renin hypertension, providing an additional stimulus to LVH induction. Calcineurin plays no role in the induction of LVH in low-renin hypertension, which is much more common clinically.
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Hong, Seonggu. "Comparison of 1-D and 2-D modeling approaches for simulating runoff and sediment transport in overload areas." Diss., This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-08272007-163824/.
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Priedeman, Jonathan Lake. "Quantifying Grain Boundary Atomic Structures Using the Smooth Overlap of Atomic Positions." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/6770.
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In this work, the relationship between grain boundary crystallography and grain boundary atomic structure is examined, using [1 0 0] - symmetric tilt grain boundaries in nickel. The structural unit model is used as a benchmark to evaluate the atomic structure description capacities of an emerging structural descriptor, the local environment representation, which itself is a refinement of the also-emergent Smooth Overlap of Atomic Positions (SOAP) descriptor. We show that the local environment representation encodes both the information of the structural unit model and additional information, such as distortion in the structural units and the arrangement of the structural units at the interface. The use of the local environment representation permits the use of a visualization tool known as SPRING to represent structural similarities between grain boundaries. With the SPRING representation, we produce objective evidence of a relationship between crystallography and atomic structure, at least for [1 0 0] - symmetric tilt grain boundaries.
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Gao, Zhi. "Sensorless Stator Winding Temperature Estimation for Induction Machines." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/13966.
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The organic materials used for stator winding insulation are subject to deterioration from thermal, electrical, and mechanical stresses. Stator winding insulation breakdown due to excessive thermal stress is one of the major causes of electric machine failures; therefore, prevention of such a failure is crucial for increasing machine reliability and minimizing financial loss due to motor failure.
This work focuses on the development of an efficient and reliable stator winding temperature estimation scheme for small to medium size mains-fed induction machines. The motivation for the stator winding temperature estimation is to develop a sensorless temperature monitoring scheme and provide an accurate temperature estimate that is capable of responding to the changes in the motors cooling capability. A discussion on the two major types of temperature estimation techniques, thermal model-based and parameter-based temperature techniques, reveals that neither method can protect motors without sacrificing the estimation accuracy or motor performance.
Based on the evaluation of the advantages and disadvantages of these two types of temperature estimation techniques, a new online stator winding temperature estimation scheme for small to medium size mains-fed induction machines is proposed in this work. The new stator winding temperature estimation scheme is based on a hybrid thermal model. By correlating the rotor temperature with the stator temperature, the hybrid thermal model unifies the thermal model-based and the parameter-based temperature estimation techniques. Experimental results validate the proposed scheme for stator winding temperature monitoring. The entire algorithm is fast, efficient and reliable, making it suitable for implementation in real time stator winding temperature monitoring.
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Braga, AntoÌ‚nio de PaÌdua. "Design models for recursive binary neural networks." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336442.
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Funiak, Stanislave. "Graphical Models and Overlay Networks for Reasoning about Large Distributed Systems." Research Showcase @ CMU, 2010. http://repository.cmu.edu/dissertations/38.
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This thesis examines reasoning under uncertainty in distributed systems. Unlike in centralizedsystems, where the observations reside in a single location, the observations in distributedsystems are often scattered across the network. To reason accurately, a networkeddevice often needs to incorporate observations from other nodes and must do so with limitedcomputation and communication even for large problems. The reasoning is further complicatedby unstable network conditions, characteristic to many real-world networks: the nodesmay fail, communication links may become unreliable, and the entire network may get fragmentedinto several components that cannot communicate with each other. These aspectsmake distributed inference very challenging.We consider one general problem of distributed filtering for estimating the state of a dynamicalsystem and three independent applications: simultaneous localization and tracking,where a camera network localizes itself by observing a moving object, internal localization oflarge-scale modular robots, where a robot determines the relative poses of its internal parts,and collaborative filtering for providing recommendations in a peer-to-peer network. Theseproblems share a common theme: each of these problems can be described by a graphicalmodel that permits compact representation of and efficient reasoning about the problem. Usinggraphical models, we design algorithms that address challenges, such as inconsistency ofnode beliefs in fragmented networks and difficult local optima in modular robot localization.Due to the complexity of the reasoning tasks, it is not sufficient to coordinate the nodes locallywithin each node’s immediate physical neighborhood. Instead, our algorithms employoverlay networks—distributed data structures built on top of the physical networks—to coordinateamong distant nodes. The resulting algorithms obey the communication constraintsimposed by the network, while solving the problems robustly.We evaluate our algorithms on data from real sensor networks and on a realistic deploymenton the PlanetLab network. We demonstrate robustness to network fluctuations and, insome cases, our distributed algorithms improve upon state-of-the-art centralized approaches.
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Li, Peng. "Utility Accrual Real-Time Scheduling: Models and Algorithms." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/11220.
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This dissertation first presents an uniprocessor real-time scheduling algorithm called the Generic Benefit Scheduling algorithm (or GBS). GBS solves a previously open real-time scheduling problem: scheduling activities subject to arbitrarily shaped, time/utility function (TUF) time constraints and mutual exclusion resource constraints. A TUF specifies the utility of completing an application activity as an application- or situation-specific function of when that activity completes. GBS considers the scheduling objective of maximizing system-wide, total accrued utility, while respecting mutual exclusion constraints. Since this problem is NP-hard, GBS heuristically computes schedules in polynomial-time.
The performance of the GBS algorithm is evaluated through simulation and through an implementation on a Portable Operating System Interface (POSIX)-compliant real-time operating system. The simulation studies and implementation measurements reveal that GBS performs close to, if not better than existing algorithms for the cases that they apply. Further, the results verify the effectiveness of GBS for its unique model. We also analytically establish timeliness and non-timeliness properties of GBS including bounds on activity utilities and mutual exclusion.
GBS targets real-time systems that are subject to significant non-determinism inherent in their operating environments e.g., completely unknown activity arrivals. When system uncertainties can be stochastically characterized (e.g., stochastic activity arrivals and execution times), it is possible to provide stochastic assurances on timeliness behavior.
The dissertation also presents algorithmic solutions to fundamental assurance problems in TUF-driven real-time systems, including stochastically satisfying individual, activity utility lower bounds and system-wide, total utility lower bounds. The algorithmic solutions include algorithms for processor bandwidth allocation and TUF scheduling. While bandwidth allocation algorithms allocate processor bandwidth share to activities to satisfy utility lower bounds, TUF scheduling algorithms schedule activities to maximize accrued utility. The algorithmic solutions and analysis are extended with a class of lock-free and lock-based resource access protocols to satisfy mutual exclusion constraints. We show that satisfying utility lower bounds with lock-based resource access protocols does not imply doing so with the lock-free scheme, and vice versa. Finally, the dissertation presents a rule-based framework for trading off assurance requirements on utility lower bound satisfaction.Ph. D.
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Zheng, Tingting. "Mathematical modeling of soil erosion by rainfall and shallow overland flow." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/9144.
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New analytical and numerical solutions are developed to both the kinematic approximation to the St Venant equations and the Hairsine-Rose (HR) soil erosion model in order to gain a better physical understanding of soil erosion and sediment transport in shallow overland flow. The HR model is unique amongst physically based erosion models in that it is the only one that: considers the entire distribution of the soil s sediment size classes, considers the development of a layer of deposited non-cohesive sediment having different characteristics to the original underlying cohesive soil and considers separately the erosion processes of rainfall detachment, runoff entrainment and gravitational deposition. The method of characteristics and the method of lines were used to develop both the analytical and numerical solutions respectively. These solutions were obtained for boundary and initial conditions typical of those used in laboratory flume experiments along with physically realistic constant and time dependent excess rainfall rates. Depending on the boundary and initial conditions, interesting new solutions of the kinematic wave equation containing expansion waves, travelling shocks as well as solutions which split into an upslope and downslope drying profiles were found. Numerical solutions of the HR model were applied to the experimental flume data of Polyakov and Nearing (2003) obtained under flow conditions which periodically cycled between net erosion and net deposition conditions. While excellent agreement was found with suspended sediment data, the analysis suggested that an additional transport mechanisms, traditionally not included in soil erosion models, was occurring. While the inclusion of bed-load transport improved the ii overall model prediction, it was still not sufficient. Subsequent asymptotic analysis then showed that the interaction of the flow with an evolving bed morphology was in fact far more important than bed load transport. A very interesting finding from this work showed that the traditional criterion of validating sediment transport model based solely on suspended sediment data was not sufficient as reliable predictions could be obtained even when important transport mechanisms were neglected. Experimental plots of sediment discharge or suspended sediment concentration against water discharge in overland flow have been shown to contain significant hysteresis between the falling and rising limbs of the discharge hydrograph. In the final Chapter, the numerical solution developed for the complete system of soil erosion and kinematic flow was used to show that it was possible for the HR model to simulate three of the four hysteresis loops identified in the literature. Counter clock-wise loops, clock-wise loops and figure 8 loops could all be produced as a result of starting with different initial conditions, being mi(x; 0) = 0, mi(x; 0) = pimt and mi(x; 0) = 0:5pimt respectively. This is the first time that these types of hysteresis loops have been produced by any erosion model. The generation of these hysteresis loops are physically explainable in terms of sediment availability and is consistent with data obtained on the field scale.
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Elsenbeer, Helmut, Daniel Lorieri, and Mike Bonell. "Mixing model approaches to estimate storm flow sources in an overland flow-dominated tropical rain forest catchment." Universität Potsdam, 1995. http://opus.kobv.de/ubp/volltexte/2008/1694/.
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Previous hydrometric studies demonstrated the prevalence of overland flow as a hydrological pathway in the tropical rain forest catchment of South Creek, northeast Queensland. The purpose of this study was to consider this information in a mixing analysis with the aim of identifying sources of, and of estimating their contribution to, storm flow during two events in February 1993. K and acid-neutralizing capacity (ANC) were used as tracers because they provided the best separation of the potential sources, saturation overland flow, soil water from depths of 0.3, 0.6, and 1.2 m, and hillslope groundwater in a two-dimensional mixing plot. It was necessary to distinguish between saturation overland flow, generated at the soil surface and following unchanneled pathways, and overland flow in incised pathways. This latter type of overland flow was a mixture of saturation overland flow (event water) with high concentrations of K and a low ANC, soil water (preevent water) with low concentrations of K and a low ANC, and groundwater (preevent water) with low concentrations of K and a high ANC. The same sources explained the streamwater chemistry during the two events with strongly differing rainfall and antecedent moisture conditions. The contribution of saturation overland flow dominated the storm flow during the first, high-intensity, 178-mm event, while the contribution of soil water reached 50% during peak flow of the second, low-intensity, 44-mm event 5 days later. This latter result is remarkably similar to soil water contributions to storm flow in mountainous forested catchments of the southeastern United States. In terms of event and preevent water the storm flow hydrograph of the high-intensity event is dominated by event water and that of the low-intensity event by preevent water. This study highlights the problems of applying mixing analyses to overland flow-dominated catchments and soil environments with a poorly developed vertical chemical zonation and emphasizes the need for independent hydrometric information for a complete characterization of watershed hydrology and chemistry.
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McConnell, Karen S. "A Model for Identifying Serial Collection Overlap in a Union List of Serials For Public Utility Libraries." NSUWorks, 1988. http://nsuworks.nova.edu/gscis_etd/712.
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Utility company libraries are scattered geographically, but serve a specific information clientele. These libraries are supported by parent companies or government entities that provide electrical, gas, and/or telephone services. In this era of increased regulation, and financial difficulties for all types of utilities, their respective library budgets are shrinking. Thus reliance on each other for interlibrary lending is increasing; but there is no ILL network, formal or informal, and no organization that would various types of utilities other than the represent the Public Utility Division (PUD) of the Special Libraries Association.
The PUD decided to create a Union List of Serials for the libraries of those members wishing to participate in the study. This investigation involved gathering the data for that list, and providing the Union List itself to the PUD. The library holdings were then analyzed to determine the resource capacity in terms of title diversity and collection overlap. The potential contributions to an interlibrary loan network were examined for the entire group, between various segments of the list, and between the trade association libraries and their individual constituents.
The existing interlibrary loan policies of the participating libraries were also examined and included in the Union List of Serials provided to the Division. Other studies have shown the relationship between collection size and overlap is linear and positively correlated, but have not dealt specifically with overlap in serial collections. This study tried to determine whether this relationship also existed for this group and for serial collections.
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Leitao, Joao Paulo Correia. "Enhancement of digital elevation models and overland flow path delineation methods for advanced urban flood modelling." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.508782.
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The objective of this thesis is to improve existing and develop new DEM enhancement methods and DEM-based overland flow delineation methods in order to generate reliable overland flow networks. These networks can be used in conjunction with existing urban drainage modelling methodologies in order to improve surface flooding simulation results. The objective has been achieved by: developing new methods to merge DEMs; evaluating nad improving available DEM enhancement methods; improving methods to solve DEM flat area problems, and developing novel methods to improve overland flow path delineation. All improvements and new developments have been adapted to the specific characteristics of high-resolution DEMs and urban catchments. The experimental work undertaken in Lisbon, together with two case-studies in the UK, was used to validate the concepts proposed in this thesis. It is concluded that DEM enhancement methods can be used to improve DEMs for overland flow delineation, thereby enhancing the reliability of urban flood modelling. The advanced flow path delineation methods developed here produce more reliable results than conventional overland flow path delineation methods. The hydraulic simulation results obtained confirm the advantages of applying 1D/1D modelling to simulate urban flood events. However, the findings show that the use of these methods needs to be preceded by a thorough analysis and quantification of Dem surface characteristics, and by a detailed calibration and validation procedure. Independent testing carried out by UKWIR has proved the adequacy and reliability of the developed methodology in full scale flood risk mapping applications.
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Sigdel, Pawan. "Improving Design Strategies for Composite Pavement Overlay: Multi-layered Elastic Approach and Reliability Based Models." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1480435567302893.
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