Dissertations / Theses on the topic 'Dual-factor'
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Bourke, Patrick Anthony. "A general factor in dual task performance decrement." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359419.
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Slobodchikoff, Tatyana G. "The Slavic Dual: Morphosyntactic Feature Economy as a Factor in Language Change." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/297021.
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Dual number marked on personal pronouns and verbal agreement suffixes disappeared in the majority of Slavic languages except for three - Slovenian, Upper Sorbian, and Lower Sorbian. Previous studies do not provide a principled account why (i) the monomorphemic dual was reanalyzed as bimorphemic in Slovenian, Upper, and Lower Sorbian, and why (ii) it was replaced by the plural in the majority of Slavic languages including Russian and Kashubian. In this dissertation, I investigate diachronic changes in the morphosyntactic category of the Slavic dual which occurred in the 11th-15th centuries. In this dissertation, I present new diachronic data obtained through digital corpora of Old Slavic manuscripts. Within the framework of Distributed Morphology, I propose a new principle of Morphosyntactic Feature Economy which explains these two different patterns of diachronic change in the Slavic dual pronouns and verbal agreement. I argue that the principle of Morphosyntactic Feature Economy is one of the factors which drives diachronic change in the category of number in Slavic languages. Morphosyntactic Feature Economy is a principle of efficient computation. It plays an essential role in restructuring of the morphosyntactic category of the Slavic dual. Morphosyntactic restructuring of the Slavic dual, triggered by its morphosyntactic and semantic markedness, results in a morphosyntactically 'simpler' category of number. As a consequence of the application of the principle of Morphosyntactic Feature Economy, the language learner acquires a featurally restructuctured category of number, which is simpler and more computationally efficient.
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McKay, Brock L. (Brock Lindsay). "Dual Factor Socially Desirable Responding and Contrasts in Intrinsic and Extrinsic Religious Motivation." Thesis, University of North Texas, 1994. https://digital.library.unt.edu/ark:/67531/metadc278762/.
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A follow-up was done to Leak and Fish's (1989) study of intrinsically and extrinsically religious individuals using Paulhus' (1984) Balanced Inventory of Desirable Responding, a two factor scale of socially desirable responding measuring self-deceptive enhancement (SDE) and impression management (IM). 275 introduction to psychology students were group tested and categorized by gender and by religious orientation with Allport and Ross's (1967) fourfold Religious Orientation Scale (ROS). Differences between the four types were hypothesized on the religious relevance of the SDE and IM scale items. A difference score was also computed by contrasting two instructional sets on the BIDR as a measure of variation across situations. Measures of private and public self-consciousness, social anxiety, fear of negative evaluation, and self esteem were included.
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Oest, Megan Elizabeth. "Dual Osteogenic and Angiogenic Growth Factor Delivery as a Treatment for Segmental Bone Defects." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/16264.
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A new model of a critically-sized segmental femoral bone defect in rats was developed to enable in vivo imaging and facilitate post-mortem mechanical testing of samples. The critically-sized nature of the model was assessed and confirmed. The efficacy of sustained co-delivery of osteogenic (BMP-2 and TGF- Ò3) and angiogenic (VEGF) growth factors in promoting functional bone repair was assessed. Effects of scaffold modification in terms of geometry and composition were evaluated. The results indicated that co-delivery of BMP-2 and TGF- Ò3 resulted in a dose-dependent improvement in functional bone repair. Modification of the polylactide scaffold to include an absorbable ceramic component and a cored out geometry enhanced rate of union. Addition of VEGF to the scaffold treatment did not significantly impact revascularization of the defect site or functional repair of the bone defect. These data demonstrate that the complex environment of an acute bone defect requires different treatment strategies than simple ectopic models would suggest. A positive predictive correlation between bone repair parameters measured in vivo and mechanical functionality was established. The novel defect model demonstrated robustness and reproducibility. Implications for further research are discussed.
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Hu, Jing. "Targeting Transcription Factor NF-kappa B by Dual Functional Oligodeoxynucleotide Complex for Inhibition of Neuroinflammation." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1439301618.
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Sarnoff, Tamar Jill. "METAPHOR, COGNITIVE ELABORATION AND PERSUASION." Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/194626.
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Metaphors have long been a subject of interest to philosophers, scholars and researchers. Recent insights into the nature and function of metaphor have spurred new interest in the persuasive effects of metaphor. To date, research on the relation between metaphors and attitudes has produced mixed findings. This paper argues that there are several limitations in previous models and designs and this work attempted to resolve several of them. The rationale for the study is based on the Elaboration Likelihood Model (ELM) of persuasion, which argues that cognitive elaboration is a strong predictor of attitudes. Researchers have posited that metaphors should evoke more cognitive elaboration than literal counterparts. This paper reports the results of a study that tested the relationship between metaphors, cognitive elaboration, and attitudes. Participants were exposed to one of 72 message conditions and responded to a set of psychological and attitude scales. Many of the hypotheses were not supported, including tests of the amount of cognitive effort that subjects reported and results related to attitude change by metaphor type. Results indicated that attitudes were stable across time, which is consistent with the ELM.
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Ogino, Shuichi. "Efficacy of the dual controlled release of HGF and bFGF impregnated with a collagen/gelatin scaffold." Kyoto University, 2018. http://hdl.handle.net/2433/231010.
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Thalji, Amanda Lynn. "A Dual-Factor Model of Mental Health in High School Students: Group Characteristics and Social Functioning." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4239.
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A dual-factor model of psychological functioning examines the presence of wellness (i.e., subjective well-being; SWB) and psychopathology (i.e., internalizing and externalizing behavior problems) in explaining youth mental health functioning. Using a dual-factor model, previous research has yielded four unique groups of elementary and middle school youth as well as college-age adults with distinct levels of wellness and psychopathology. The present empirical investigation included valid data from 500 adolescents from two high schools (grades 9 to 11). This exploratory study produced four groups of students with unique mental health profiles aligned with previous studies investigating the dual-factor model. Tukey-Kramer comparisons determined that among groups classified as having elevated symptoms of psychopathology, those that also report high levels of SWB (i.e., symptomatic but content youth) are more likely to be rated as having externalizing problems, and those with low levels of SWB (i.e., troubled youth) are more likely to report symptoms of internalizing problems. Evaluation of group differences on positive mental health indicators suggest that differences between groups with elevated SWB versus low SWB were due to differences in life satisfaction and negative affect. Tukey-Kramer comparisons indicated that youth with complete mental health reported optimal functioning in terms SWB. Youth identified as having low levels of SWB, appeared to report similarly low levels of life satisfaction and positive affect, but those that also reported elevated levels of psychopathology, particularly internalizing problems, had greater levels of negative affect. Additional findings from this study demonstrate the utility of classifying high school students' mental health according to a dual-factor model. Results of a MANCOVA suggest a significant effect for mental health group membership as yielded from a dual-factor model on students' social-functioning. Follow up ANCOVAs and Tukey-Kramer comparisons suggest that high SWB in tandem with low levels of psychopathology (i.e., complete mental health) is associated with a host of optimal functioning in terms of teacher-rated social skills, perceptions of interpersonal relationships, receipt of social support, reduced likelihood of victimization, and high quality romantic experiences. For youth with psychopathology, average to high levels of SWB (i.e., as in symptomatic but content students), may buffer them from experiencing poor social functioning, particularly in terms of perceived social support, peer victimization, general interpersonal relations, and satisfaction with romantic experiences. Overall results from this study support the presence of dual-factor model in high school students and the importance of assessment of positive and negative indicators in order to effectively gain a comprehensive understanding of adolescents' social functioning.
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Ebisine, Kimimuepigha. "Dual regulation of transcription factor Nrf2 by Keap1 and the beta-TrCP/GSK-3 in cancer." Thesis, University of Dundee, 2019. https://discovery.dundee.ac.uk/en/studentTheses/20338051-4e92-417e-aeb1-4cd3dc86eda4.
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Cancer is one of the foremost causes of death worldwide with about 14.1 million new incidences and 8.2 cancer related deaths occurring globally. NF-E2 p45-related factor 2 (Nrf2), a cap-'n'-collar basic leucine zipper (CNC-bZIP) transcription factor, prevents carcinogenesis through expression of genes that ensure the excretion, enzymatic modification, and repair of oxidative damage in cells containing the antioxidant response element (ARE) in their promoter region. Beyond providing cytoprotection against oxidative stress and xenobiotics, Nrf2 pays a role in maintaining basic physiological processes such as energy metabolism and cell cycle regulation. Whilst Nrf2 plays a pivotal role in preventing degenerative and inflammatory disease, upregulation of Nrf2 promotes tumourigenesis in cancerous cells. Therefore, understanding the mechanisms controlling Nrf2 activity is important in translational medicine. Nrf2 is regulated by proteasomal degradation by Kelch-like ECH-associated protein 1 (Keap1) an E3 ubiquitin ligase substrate adaptor protein that recruits of cullin-3 (Cul3) to Nrf2 via its Neh2 domain. Nrf2 is also negatively regulated by phosphorylation by glycogen synthase kinase-3 (GSK-3) causing β-transducin repeat-containing protein (β-TrCP) to ubiquitinate Nrf2 by Skp1-Cul1-F-box (SCF) ubiquitin ligase through the Neh6 domain of Nrf2. Several research groups have shown that induction of ARE-driven genes can be regulated by phosphoinositide 3- kinase- protein kinase B (PI3K-Akt/PKB) signalling pathway. The ability of tert-butylhydroquinone (tBHQ), 1-[2-cyano-3,12-dioxooleana-1,9(11)-diene-28-oyl]imidazole (CDDO-Im), diethyl maleate (DEM), curcumin, carnosol, ferulic acid and sulforaphane (SFN) to activate Nrf2-target genes in a Keap1-dependent or Keap1-independent manner was tested. It was discovered that all compounds, except for SFN, activate Nrf2-target genes in a Keap1-independent manner, inhibiting GSK-3 and functioning through the Neh6 domain of Nrf2. Analysis of the involvement of PI3K-Akt/PKB pathway in Nrf2 activation revealed that regulation of Nrf2 through the PI3K-Akt/PKB pathway is independent of Keap1 but dependent on GSK-3. Also, it was shown that tBHQ, DEM, CDDO-Im, curcumin, ferulic acid directly decreased phosphatase and tensin homolog (PTEN) activity, thereby preventing formation of the phosphodegron in the Neh6 domain of Nrf2. With increased Nrf2 levels reported in various cancers including lung cancer, leading to the progression of these cancers, Nrf2 can be seen as a double-edged sword. Loss-of-function somatic mutations in KEAP1 as well as somatic mutation in NFE2L2 has been reported in several human cancers playing a role in the development of such cancer. Using short hairpin RNA (shRNA) and the CRISPR/Cas9 system to generate stable Nrf2 knockdown A549 and H460 cells, the second part of this thesis investigated biochemical and physiological changes that occur, when the Nrf2 is genetically downregulated, and further on to determine what mechanism(s) is responsible for decreased cell proliferation in tumours. The findings obtained confirm that downregulation of Nrf2 from the human non-small lung adenocarcinoma epithelial cell line A549 and H460, in which Nrf2 is upregulated though somatic mutations in KEAP1, results in decreased cell proliferation. Analysis of the genes involved in NADPH generation and pentose phosphate pathway (PPP) show that decrease in Nrf2 caused a decrease in the expression of genes involved in PPP. Although knockdown of Nrf2 resulted in a decrease in cell proliferation, it was shown that this decrease was not as a result of cell death. Nrf2 is able to control cell proliferation by induction of metabolic reprogramming geared towards favoring anabolic pathways and influencing the PPP as well as provide energy source required for cell proliferation.
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Yehya, Alaa. "New insights into Brain-derived Neurotrophic Factor Dual Signaling : imbalance implications in mechanisms of neuroprotection and neurotoxicity." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS058.
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Le « Brain-Derived Neurotrophic Factor » (BDNF) est la neurotrophine la plus abondante et la plus répandue dans le cerveau humain. De nombreuses études se sont intéressées à son rôle dans la survie neuronale, la croissance et la plasticité synaptique. La signalisation BDNF est dépendante de deux récepteurs, le récepteur tyrosine kinase (TrkB) et le récepteur neurotrophine p75 (p75NTR). Il est bien établi que le rôle trophique du BDNF est assuré via son récepteur de haute-affinité TrkB, alors que la forme précurseur proBDNF active p75NTR vers la voie d'apoptose. Cette double signalisation est physiologiquement contrôlée par un équilibre entre les différentes voies. Les résultats obtenus à partir des études cliniques et des modèles animaux suggèrent un rôle de la signalisation BDNF dans les tauopathies, caractérisées par l'existence de dépôts intracérébraux de protéine tau, une caractéristique commune à certaines maladies neurodégénératives, notamment la maladie d'Alzheimer (MA). Cependant, aucune investigation n'a été menée jusqu'à présent sur les modifications que pouvaient induire les tauopathies dans la signalisation BDNF et si une dérégulation de l'expression du BDNF pouvait affecter ses propres récepteurs TrkB et p75NTR.Dans ce travail de thèse, nous avons utilisé une lignée de poisson-zèbre transgénique portant la mutation humaine TAUP301L retrouvée notamment dans le démence fronto-temporale. Nous avons mesuré l'expression de BDNF et de ses deux récepteurs au niveau transcriptionnel et protéique. Nous n'avons observé aucune modification des taux d'expression de BDNF et de TrkB, en revanche, nous avons noté une augmentation significative de p75NTR. A l'aide de la même lignée transgénique, nous avons induit une baisse d'expression de BDNF via la micro-injection de morpholinos. De manière remarquable, la baisse d'expression de BDNF affecte de façon différentielle TrkB et p75NTR. En effet, nous avons observé une diminution de l'expression de TrkB et parallèlement une augmentation de p75NTR. De plus, la baisse d'expression de BDNF aggrave la neurotoxicité associée au développement de la tauopathie ce qui se traduit par une augmentation de la mort neuronale et de l'hyperphosphorylation de tau, cette dernière étant concommittante à une activation de la Glycogen Synthétase Kinase 3 beta (GSK3beta).Une diminution de l'effet neuroprotecteur de BDNF à travers un déséquilibre de ces récepteurs de signalisation a été également montré en étudiant le rôle de BDNF au cours du développement de la ligne latérale postérieure (PLL). Ce système est considéré comme un modèle d'étude particulièrement pertinent pour évaluer différents processus biologiques comme la migration cellulaire collective ou la régénération cellulaire. Nous avons détecté l'expression de BDNF dans plusieurs structures de la PLL. La diminution d'expression de BDNF conduit à un défaut de migration du primordium de la PLL, associé à une augmentation de la mort cellulaire. De plus, nous avons observé une réduction de la prolifération cellulaire et un défaut de repousse axonale du nerf, ce qui conduit à des anomalies de régénération à la fois du nerf de la PLL et des cellules ciliées. Nos résultats suggèrent que le BDNF joue un rôle essentiel au cours du développement de la PLL et démontrent la pertinence du système de la ligne latérale en tant que modèle d'étude des fonctions de BDNF.En conclusion, notre étude représente la première analyse du rôle in vivo de BDNF et de ses 2 récepteurs de signalisation. Nous avons ainsi montré les répercussions d'une dérégulation des voies de signalisation du BDNF. Un équilibre entre ces deux voies est essentiel pour le développement et la survie cellulaire, ce qui fait de BDNF non seulement une cible thérapeutique potentielle, mais également une neurotrophine clé pouvant activer plusieurs circuits de signalisation, potentialisant ainsi son rôle protecteurBrain-derived neurotrophic factor (BDNF) is the most abundant secreted and widely distributed neurotrophin in human brain. It has been extensively studied for its role in neuronal survival, growth and synaptic plasticity. BDNF signaling mediated through tryosine receptor kinase B (TrkB) and p75NTR neurotrophin receptor (p75NTR). It is well established that BDNF beneficial actions are mediated by it is high-affinity TrkB, whereas pro-BDNF activates p75NTR towards apoptosis. This diverse dual signaling is normally under a tight balance regulation. Based on clinical and animal studies, it has been suggested that BDNF signaling is involved in tauopathy, which is a pathological hallmark in several neurodegenerative diseases, including Alzheimer's disease (AD). However, what changes tauopathy may induce on BDNF signaling, and whether BDNF deregulation could affect its two signaling receptors (TrkB, p75NTR), and eventually tauopathy pathogenesis, have not been investigated. In this study we used a transgenic zebrafish line for human Tau-P301L tauopathy, and measured transcriptional and protein levels of BDNF and of its two signaling receptors. We found no modification of BDNF and TrkB expression levels, but a significant up-regulation of p75NTR. We then used the same transgenic line to generate BDNF knockdown using morpholino microinjection technique. Interestingly, BDNF knockdown differentially affects TrkB and p75NTR; we observed a reduction of TrkB expression and an increase in p75NTR expression. In addition, BDNF knockdown aggravates tauopathy-associated toxicity; we found an increase in neuronal cell death and tau hyperphosphorylation, the latter was accompanied by an activation of tau glycogen synthase kinase 3beta (GSK3beta). Attenuation of BDNF neuroprotective effects through imbalance of its signaling receptors was further highlighted through studying BDNF role in the development of zebrafish posterior lateral line system (PLL). This system has recently emerged as a powerful tool to study several dynamic biological processes, including collective cell migration and nerve/hair cells regeneration. We detected BDNF expression in different PLL components. BDNF knockdown led to an impairment of the PLL primordium migration due to concomitant increase in cell death rate. In addition, reduced cell proliferation and defect in axonal re-growth were observed , which led to major defects of PLL nerve/hair cells regeneration, respectively. These findings suggest that BDNF has an essential role in PLL development, but more important they introduce PLL as research model to study BDNF functions. This is the first study to provide a detailed in vivo analysis of BDNF and its two signaling receptors. Our findings highlight several implications of BDNF signaling deregulation. Balanced signaling clearly has essential roles in survival and development, in addition to being a therapeutic target, BDNF can itself activate diverse molecular pathways, thus setting up a potential circuitry that could enhance its protective role
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Thalji, Amanda L. "Predicting Early Adolescents’ Academic Achievement and In-School Behavior with a Dual-Factor Model of Mental Health." Scholar Commons, 2010. https://scholarcommons.usf.edu/etd/1787.
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A dual-factor model of mental health includes indicators of wellness (i.e., subjective well-being) and psychopathology (i.e., internalizing and externalizing behavior problems) in defining psychological wellness. The present empirical investigation examined the utility of SWB and psychopathology examined separately and together (as in a dual-factor model of mental health) in predicting students' subsequent academic achievement and in-school behavior. Specifically, it determined if SWB, psychopathology, and membership in a specific mental health group yielded by the dual-factor model (i.e., complete mental health, vulnerable, symptomatic but content, or troubled) at Time 1 was related to achievement (i.e., GPA, FCAT-math, FCAT-reading, absences, office disciplinary referrals [ODRs]) the following school year (i.e., Time 2). A previously analyzed data set (Time 1) and a different archival data set yielded from student records unique to the current study (Time 2) comprised of data from 300 adolescents were analyzed. Results of regression analyses to explore the predictive initial relationship of mental health to later student achievement indicated that initial SWB predicted student grades one year later, initial internalizing psychopathology predicted absences one year later, and initial externalizing psychopathology predicted grades, absences, and ODRs one year later. Results of mixed model ANCOVAs indicated that students' grades and attendance across time varied as a function of mental health group. Specifically, students belonging to the troubled mental health group declined at a significantly faster rate than youth without psychopathology across time on GPA. In contrast, the slope of students in the symptomatic but content group was not significantly different from the slope of peers with low psychopathology. Additionally, at Time 2, the best school attendance and school grades were found by students who had both average/high SWB and low psychopathology one year earlier, supporting the long-term utility of complete mental health.
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Shaffer, Emily J. "An investigation of a dual-factor model of mental health and related physical health outcomes among early adolescents." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001757.
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Brown, Serena Jean Silver. "Dual functions of the retinal determination gene network member EYES ABSENT as a transcription factor and protein phosphatase." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/33454.
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Lind, Joakim, and Lars Sparre. "Investigating New Multifactor Models with a Conditional Dual-Beta : Can a Conditional Dual-Beta in the Market Factor add Explanatory Value in New Multifactor Models? A study of the Swedish Stock Market between 2003 and 2015." Thesis, Linköpings universitet, Företagsekonomi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-129987.
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This thesis investigates pricing-performance of two recently developed multifactor asset-pricing models with the implementation of dual-betas dependent upon prevailing market-conditions. The models included in the study are the Fama and French five-factor model and the Q-factor model by Hou, Xue and Zhang. We test the models on cross-sectional Swedish stock-market data between 2003 and 2015 from the Large-, Mid- and Small Cap-lists and their respective precursors. The models are tested in their ability to explain portfolios sorted on firm beta-values, on a twelve-year period as well as a six-year period characterized by changing market directions and high market volatility. In our study, we support the presence of changing risk-return relationship in up and down market states by estimating separate market betas with the risk-free rate as threshold. However, we do not find the isolated and volatile period to give rise to a larger difference in the up and down market betas. We consistently find the models to have a decreasing explanatory power on the portfolios of firms with lower beta values. We also find the largest difference in the up and down market betas occurring in the low beta portfolios, suggesting that this is causing measurement problems in the models. While making the models conditional, the measurement problem with the static beta seems to be reduced for the portfolios where the difference between up and down betas differ most. In the applied context, we conclude the conditional dual beta adds explanatory power in the models when the market beta differs in up and down market states. The insights of this thesis support the method of making the market-beta conditional as suggested by Pettengill, Sundaram & Mathur (Pettengill, et al., 1995), in new multifactor models.
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Kauer, Michaela [Verfasser], Ralph [Akademischer Betreuer] Bruder, and Joachim [Akademischer Betreuer] Vogt. "Identification as Determining Factor of Technology Acceptance for Hedonic and Dual Use Products / Michaela Kauer. Betreuer: Ralph Bruder ; Joachim Vogt." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2012. http://d-nb.info/1106117921/34.
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Naples, Lauren Hunter. "Neurodivergence in Early Childhood| Deriving a Dual-Factor Model of Educational Well-Being Through a Design-Based Research Pilot Program." Thesis, The George Washington University, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=13813592.
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There is a distinct need to understand subjective well-being for neurodivergent students in early childhood. Review of previous literature suggests the positive influence of subjective well-being in mitigating psychological distress; however, young children have been excluded from these investigations. Therefore, this study employed an advanced mixed methods research design, through which a convergent core was embedded within an overarching quasi-experimental framework to analyze three key outcomes in early childhood education: (a) self-identified conceptualizations of student covitality, (b) self-evaluated levels of student covitality, and (c) teacher-rated levels of executive dysfunction.
All students actively enrolled in a local partner school serving pre-Kindergarten to 2nd grade (N = 45) participated in qualitative and quantitative evaluations of covitality. Qualitative data were collected through semi-structured focus groups, and quantitative data were collected through student ratings on the Social-Emotional Health Survey-Primary (Furlong, You, Renshaw, O’Malley, & Rebelez, 2013). Qualitative findings suggested students conceptualize covitality as positive school experiences along a developmental trajectory across five themes—play activities, classroom instruction, school environmental factors, interpersonal relationships, and special programs. Quantitative results determined excellent internal reliability of the covitality scale for early elementary 1st- and 2nd-grade students (Cronbach's α = .908).
Two classrooms were randomly assigned to the waitlist control ( n = 14) or intervention (n = 10) condition—1st- and 2nd-grade, respectively. A novel positive psychology intervention was designed and tested to promote covitality. Implementation of strategically targeted practices supported the underlying factors of gratitude, zest, optimism, and persistence.
Additional quantitative data were collected through teacher ratings of cognition on the Behavior Rating Inventory of Executive Function, Second Edition (Gioia, Isquith, Guy, & Kenworthy, 2016). Intervention effects indicated a statistically significant interaction for improved executive functioning relative to the waitlist control group (p = .011). Integration of qualitative and quantitative results produced preliminary evidence of categorical advancement in a dual-factor clinical classification system and distinctions in varied and nuanced conceptualizations of well-being constructs over time. Synthesis of qualitative, quantitative, and integrated findings highlighted the value of design-based research generally, and the Student Strengths Safari© program, specifically, to establish a dual-factor model of educational well-being (EdWB) for optimal student development.
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Smith, Nicholas David W. "An Application of the Dual Factor Model of Mental Health in Elementary School Students: Implications for Social Functioning and Psychopathology." Scholar Commons, 2018. http://scholarcommons.usf.edu/etd/7231.
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In the study of positive psychology and mental health there has been greater emphasis placed on the presence of indicators of well-being, as opposed to previous models solely based on the presence or absence of psychopathological symptoms. This has yielded a model titled the Dual Factor Model of Mental Health (DFM; Suldo, 2016). Psychopathological symptoms have been conceptualized as a categorical variable encompassing an elevated level of symptoms of either externalizing or internalizing disorders. Complete Mental Health (CMH) is generally conceptualized as having low psychopathology (PTH) and high subjective well-being (SWB). Previous research has indicated more positive outcomes, such as academic achievement and supportive social relationships, are associated with CMH. The DFM has been examined in adolescents and young adults, however, only one study has identified the model in elementary school students (Greenspoon & Saklofske, 2008). The current study completed secondary analysis of an archival data set (Hearon, 2017) to examine the distribution of the DFM in a sample of 178 elementary school students (grades 4th and 5th) and the impact that mental health group status had on social functioning levels with teachers and classmates. Results from this study indicated the DFM was present in a sample of elementary school students, with the majority of participants being classified in the CMH group, consistent with previous literature. Additionally, regarding students’ perceived social support of classmates and teachers, those groups with elevated levels of SWB reported greater mean values than those groups that had decreased levels of SWB. Finally, between group differences in terms of psychopathology were present, whereas within group differences in terms of externalizing and internalizing behavior were not present in any group. Implications for school psychologists, such as the importance of assessing SWB in tandem with psychopathology are presented. Finally, limitations of this study (i.e., nested data) and avenues for future research (i.e., mental health status predicting peer networks, continued evaluation of DFM psychopathology make-up) are reviewed.
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Frank, Michael James. "Youth Character Strengths, Peer Victimization, and Well-Being: Understanding Associations between Positive Traits, Social Experiences, and Positive Psychological Outcomes." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5481.
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The advent of positive psychology has increased awareness of factors that lead individuals to thrive in life, allowing for a more comprehensive model of mental health service delivery. However, while measurement and understanding of character strengths and well-being have improved over the last decade, the interaction of these factors with social risk factors is not entirely understood. The current study analyzed an archival dataset consisting of self-report data from 425 high school students, to examine the extent to which high school students' specific character strengths (i.e., social competence, self-regulation, responsibility, and empathy) are associated with positive psychological outcomes (i.e., gratitude, life satisfaction, and hope), and moderate the relationships between positive psychological outcomes and relational and overt peer victimization. All measured character strengths were positively associated with life satisfaction and hope except for empathy, which was negatively associated with both in multivariate analyses. Social competence and self-regulation were positively associated with gratitude. Relational victimization (but not overt victimization) was inversely associated with life satisfaction and gratitude, and indirectly predicted hope as mediated by gratitude. Gratitude and hope predicted life satisfaction in both models, and served as partial mediators of character strengths and relational victimization. For overt victimization, social competence served as a protective factor and self-regulation served as a risk factor to gratitude. For relational victimization, self-regulation served as a protective factor to gratitude. Implications for research and practice are discussed.
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Jadlowsky, Julie Kendal. "Dual Control of HIV Transcription Elongation: Virus-Specific Negative Control by NELF-E is Counterbalanced by Positive Transcription Factor P-TEFb." Case Western Reserve University School of Graduate Studies / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1228234927.
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Jadlowsky, Julie Kendal. "Dual control of HIV transcription elongation virus-specific negative control by NELF-E is counterbalanced by positive transcription factor P-TEFb /." Cleveland, Ohio : Case Western Reserve University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1228234927.
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Cook, Peter Joseph. "Eya a dual function nuclear factor crucial for regulation of developmental gene expression and prevention of apoptosis in response to genotoxic stress /." Diss., [La Jolla, Calif.] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3344509.
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Thesis (Ph. D.)--University of California, San Diego, 2009.Title from first page of PDF file (viewed March 13, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Beltrame, Fernando. "Análise comparativa de conversores monofásicos aplicados a correção de fator de potência." Universidade Federal de Santa Maria, 2009. http://repositorio.ufsm.br/handle/1/8473.
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This work presents a study and a comparative analysis of high power single-phase converter applied to power factor correctioii in according to the international standards IEC
61000-3-4 (harmonics limitation) and CISPR 22 (electromagnetic interference limitation) for high power applications. The converters studied were the conventional boost converter, the interleaved boost converter, with two cell operating with a delay angle of 180" between each
other, and the dual boost converter. Such converters are used in front-end modules of information technology equipment. AI1 converters have the same input and output voltage and the same input current. The converters were projected to provide the same total input harmonic distortion (THD), with the idea of using the same input filter. Implementation of the control laws was performed through a digital control with the use of a 16 bits microcontroller. A11 converters were, first of all, studied and presented in this dissertation. The
analyzed parameters for comparison were: power factor, total harmonic distortion (THD), semiconductor losses and magnetic losses, heat-sinks volume and magnetics volume,
conducted electromagnetic interference, performance and costs.Esse trabalho apresenta um estudo e uma análise comparativa de conversores monofásicos aplicados i correção de fator de potência que estejam de acordo com as normas internacionais IEC 61000-3-4 (limitação de harmônicos) e CISPR 22 (limitação dos níveis de interferência eletromagnética) para aplicações de alta potência. Os conversores estudados foram os conversores Boost, o conversor Boost Intercalado, com duas células operando com uma defasagem de 180" entre si, e o conversor Dual Boost. Tais conversores são utilizados como estágio de entrada em fontes de equipamentos da tecnologia da informação. Todos os conversores apresentam a mesma tensão de entrada e saída, e a mesma corrente de entrada. Os conversores foram projetados para apresentarem a mesma taxa de distorção harmônica da corrente de entrada (THD) para que, dessa forma, todos tenham o mesmo filtro de entrada. A implementação das leis de controle foi realizada através de um controlador digital com o uso de um microcontrolador de 16 bits. Todos os conversores foram primeiramente estudados e são apresentados nesta dissertação. Os parâmetros analisados para a comparação das topologias foram: fator de potência, taxa de distorção harmônica, perdas nos dispositivos semicondutores e magnéticos, volume dos dissipadores e materiais magnéticos, interferência eletromagnética conduzida, eficiência e custos.
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Mcmahan, Melanie M. "A Longitudinal Examination of High School Students' Group Membership in a Dual-Factor Model of Mental Health: Stability of Mental Health Status and Predictors of Change." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4369.
Full textAbstract:
A dual-factor model of mental health includes indicators of wellness (i.e., subjective well-being; SWB) and psychopathology (i.e., internalizing and externalizing behavior problems) in defining youth mental health. In this model, four categories of psychological functioning with distinct levels of SWB and psychopathology emerge, including two that are overlooked (i.e., Vulnerable and Symptomatic but Content) in traditional assessments that assume SWB and psychopathology are opposite ends of the same continuum. The present study investigated the 1-year stability of adolescent mental health as classified by a dual-factor model, and identified predictors of stability and change, in a sample of 425 high school students. Results included that 60% of the high school students remained in the same mental health group over both time points. The Complete Mental Health Group (i.e., high SWB and low psychopathology) showed the most stability over time as nearly 80% of students initially in this group retained that mental health profile one year later. The initially Symptomatic but Content group (i.e., high SWB and high psychopathology) showed the least stability, with only 17% of students remaining in this mental health group the following year. Higher socioeconomic status and lower neuroticism reliably and uniquely predicted which students who initially experienced Complete Mental Health remained that way. Low neuroticism also predicted which students with partial mental health initially (i.e., Vulnerable or Symptomatic but Content) improved to Complete Mental Health. Once the shared variance amongst factors had been accounted for, no factors reliably and uniquely predicted which students initially Troubled stayed that way, nor which students moved from partial mental health (i.e., Vulnerable, Symptomatic but Content) to Troubled. This study contributes to the literature by providing the first examination of the stability of high school students' mental health as defined by a dual-factor model. Additionally, this study provides insight into the factors which predict students' stability and movement across mental health groups over time. Both sets of findings can be useful for school-based mental health professionals' prevention and intervention work with regard to how to operationalize student mental health, and intrapersonal risk factors important to detect.
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Birchenough, Holly. "Investigation of the tumour necrosis factor-stimulated gene-6 (TSG-6) interactome : use and development of surface sensitive techniques." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/investigation-of-the-tumour-necrosis-factorstimulated-gene6-tsg6-interactome-use-and-development-of-surface-sensitive-techniques(4866db6a-fd8e-4831-babb-b4d3c11307e3).html.
Full textAbstract:
Tumour necrosis factor-stimulated gene-6 (TSG-6) is a protein expressed in a wide range of cell types and tissues, predominantly in response to inflammatory stimuli. The expression of TSG-6 is believed to be associated with the protection of tissues from the damaging effects of inflammation. In animal models treatment with TSG-6 protein has been found to reduce inflammatory damage in myocardial infarction, corneal injury and arthritis. Endogenous TSG-6 production has been suggested to play a protective role in inflammatory arthritis and has been implicated in bone homeostasis. The expression of TSG-6 is also essential in the process of cumulus matrix formation that occurs around the oocyte in the periovulatory period and is necessary for successful ovulation and fertilisation. In many cases the mechanism underlying a particular TSG-6 function is not fully understood. TSG-6 has numerous binding partners including the serum glycoprotein inter-alpha-inhibitor (IαI), the growth factor bone morphogenetic protein-2 (BMP-2) and the extracellular matrix protein fibronectin, as well as glycosaminoglycans (GAGs) such as hyaluronan and heparan sulphate (HS). The TSG-6 protein is mostly composed of contiguous Link and CUB domains, with the majority of ligand binding sites identified within the Link module. The CUB domain of TSG-6 has been less extensively studied. Here biophysical techniques have been used to investigate the TSG-6 interactome including both the Link module and CUB domain. Intrinsic fluorescence spectroscopy was used to establish the metal-ion binding properties of the CUB domain, which was established to have a high affinity Ca2+-binding site. Using surface plasmon resonance (SPR), a novel metal-ion dependent interaction was found for the CUB domain of TSG-6 and the heavy chains (HCs) of IαI. Investigation using mutants of both the CUB domain of TSG-6 and HC of IαI established that the metal-ion binding sites within each protein are involved in the interaction. SPR analysis was also used to define the affinities and binding sites for TSG-6 interactions with fibronectin and BMP-2. High affinity interactions between TSG-6 ligands were also revealed (e.g. BMP-2 and HC, fibronectin and HC) and their binding sites defined. The discovery of the novel interactions between these TSG-6 ligands suggests crosstalk within the TSG-6 interactome, with the potential for ternary complex formation or indeed hierarchical orders of binding. Thus work was undertaken to develop a passivated lipid bilayer platform for use with surface sensitive techniques. This platform was used to investigate the hierarchy of protein and GAG interactions using quartz crystal microbalance with dissipation monitoring (QCM-D) and dual polarisation interferometry (DPI). The investigation revealed a novel role for the Link module of TSG-6 in heparin condensation, potentially via protein dimerisation and/or oligomerisation which could affect heparin/HS functions within the extracellular matrix (ECM). Thus the biophysical analysis of TSG-6 presented here has identified novel interactions and functions of TSG-6 which may provide mechanisms for the protective functioning of TSG-6 in inflammation and its ECM structuring role in ovulation.
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Springer, Sheila, and Sheila Springer. "Effects of Media Use on Bereavement." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/626158.
Full textAbstract:
This study applies bereavement and media use theoretical perspectives to examine how survivors use media to cope with spousal loss during the first two years. Specifically, this study explores whether survivors’ television use is associated with grief intensity. Potential associations between television use and grief intensity are explored using an online survey. A media use for coping scale is developed. The relationship between television oscillation (i.e., equal use of television for respite, and to cope with primary and secondary stressors) and grief intensity is also explored, and ten specific moderators of this relationship are examined: recency of loss, type of loss, social support, family proximity and contact, marital relationship quality, economic stability, pre-existing physical and mental health issues, and change in television use.
Results were collected from 356 spousal survivors and indicate that television use to cope is associated with grief intensity. Survivors that report high television use in general are using more television for relaxation, companionship, acceptance, positive reinterpretation and growth, and emotional and instrumental support. The most dramatic effects are observed with television use for relaxation and companionship, and the smallest effects with television use for emotional and instrumental support. However, there was no association between television use for respite, or to cope with primary and secondary stressors and grief intensity. Results support the value of social support, family contact at the time of loss, fewer physical health issues, and decreasing general television use in promoting more positive bereavement outcomes.
Results support television oscillation as a predictor of grief intensity, but only under certain circumstances. Four of the models show significant moderator effects between television oscillation and grief intensity: social support at the time of loss, family contact at the time of loss, pre-existing physical health issues, and change in television use since the loss. When survivors have less social support at the time of loss, television oscillation is associated with less grief intensity as predicted. However, when survivors have more social support, television oscillation is marginally associated with more grief intensity. Likewise, when survivors have less family contact, television oscillation is associated with less grief intensity as predicted. Conversely, when survivors have more family contact, television oscillation is associated with more grief intensity. When survivors have more pre-existing physical health issues, television oscillation is not associated with grief intensity as predicted. For survivors with fewer pre-existing physical health issues, television oscillation is associated with less grief intensity. When survivors decrease television use by approximately one hour, television oscillation is marginally associated with less grief intensity. On the other hand, when survivors increase television use, television oscillation is not associated with grief intensity. Current general television use was a highly significant control variable in all moderator analyses indicating more television use to cope is associated with more grief intensity.
Recency, type of loss, marital relationship quality, family proximity, economic stability, and pre-existing mental health issues did not significantly moderate the relationship between television oscillation and grief intensity.
This study extends previous work by merging the bereavement and media use literatures, and in the development of a media use for coping scale. Moreover, it provides important empirical evidence on theoretical models about bereavement. This expands the potential for discussions about the association of individual vulnerabilities with more positive bereavement outcomes.
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Eslami, Aida. "Analyse factorielle de données structurées en groupes d'individus : application en biologie." Thesis, Rennes 1, 2013. http://www.theses.fr/2013REN1S091.
Full textAbstract:
Ce travail concerne les analyses visant à étudier les données où les individus sont structurés en différents groupes (données multi-groupes). La thèse aborde la question des données multi-groupes ayant une structure en un seul tableau, plusieurs tableaux, trois voies et deux blocs (régression). Cette thèse présente plusieurs méthodes d'analyse de données multi-groupes dans le cadre de l'analyse factorielle. Notre travail comporte trois parties. La première partie traite de l'analyse de données multi-groupes (un bloc de variables divisé en sous-groupes d'individus). Le but est soit descriptif (analyse intra-groupes) ou prédictif (analyse discriminante ou analyse inter-groupe). Nous commençons par une description exhaustive des méthodes multi-groupes. En outre, nous proposons deux méthodes : l'Analyse Procrustéenne duale et l'Analyse en Composantes Communes et Poids Spécifiques duale. Nous exposons également de nouvelles propriétés et algorithmes pour l'Analyse en Composantes Principales multi-groupes. La deuxième partie concerne l'analyse multi-blocs et multi-groupes et l'analyse trois voies et multi-groupes. Nous présentons les méthodes existantes. Par ailleurs, nous proposons deux méthodes, l'ACP multi-blocs et multi-groupes et l'ACP multi-blocs et multi-groupes pondérée, vues comme des extensions d'Analyse en Composantes Principales multi-groupes. L'analyse en deux blocs et multi-groupes est prise en compte dans la troisième partie. Tout d'abord, nous présentons des méthodes appropriées pour trouver la relation entre un ensemble de données explicatives et un ensemble de données à expliquer, les deux tableaux présentant une structure de groupe entre les individus. Par la suite, nous proposons quatre méthodes pouvant être vues comme des extensions de la régression PLS au cas multi-groupes, et parmi eux, nous en sélectionnons une et la développons dans une stratégie de régression. Les méthodes proposées sont illustrées sur la base de plusieurs jeux de données réels dans le domaine de la biologie. Toutes les stratégies d'analyse sont programmées sur le logiciel libre RThis work deals with multi-group analysis, to study multi-group data where individuals are a priori structured into different groups. The thesis tackles the issue of multi-group data in a multivariate, multi-block, three-way and two-block (regression) setting. It presents several methods of multi-group data analysis in the framework of factorial analysis. It includes three sections. The first section concerns the case of multivariate multi-group data. The aim is either descriptive (within-group analysis) or predictive (discriminant analysis, between-group analysis). We start with a comprehensive review of multi-group methods. Furthermore, we propose two methods namely Dual Generalized Procrustes Analysis and Dual Common Component and Specific Weights Analysis. We also exhibit new properties and algorithms for multi-group Principal Component Analysis. The second section deals with multiblock multi-group and three-way multi-group data analysis. We give a general review of multiblock multi-group methods. In addition, we propose two methods, namely multiblock and multi-group PCA and Weighted-multiblock and multi-group PCA, as extensions of multi-group Principal Component Analysis. The two-block multi-group analysis is taken into account in the third section. Firstly, we give a presentation of appropriate methods to investigate the relationship between an explanatory dataset and a dependent dataset where there is a group structure among individuals. Thereafter, we propose four methods, namely multi-group PLS, in the PLS approach, and among them we select one and develop it into a regression strategy. The proposed methods are illustrated on the basis of several real datasets in the field of biology. All the strategies of analysis are implemented within the framework of R
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Sun, Peng. "Semiparametric Bayesian Approach using Weighted Dirichlet Process Mixture For Finance Statistical Models." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/78189.
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Patterson, Jennifer. "Nurse Supervisors and Certified Nursing Assistants: Leadership Characteristics and Job Satisfaction." ScholarWorks, 2018. https://scholarworks.waldenu.edu/dissertations/5583.
Full textAbstract:
Significant costs are associated with the turnover rate of certified nursing assistants (CNAs) in skilled nursing facilities (SNFs), and turnover impacts the quality of care for residents of the SNFs through disruption of care. The purpose of this quantitative cross-sectional study was to identify the leadership characteristics of supervisors most associated with the job satisfaction (JS) of CNAs in SNFs. Herzberg's dual factor theory was used as the theoretical framework to explain the relationship between the leadership characteristics and the associated JS. The research question was used to examine the independent variables of trust, teamwork, supportive supervision, leader-follower relationships, and empowerment of supervisors in SNFs that help predict the dependent variable, JS of CNAs. A random sampling of the population of CNAs from 120-bed SNFs located in Florida completed online surveys that included the Organizational Trust Inventory, the Conditions for Work Effectiveness Questionnaire II, and the Benjamin Rose Nurse Assistant Job Satisfaction Scale. Multiple linear regression was used to analyze data to determine the effects of the leadership characteristics on the JS of CNAs in SNFs. Results indicated that the increased levels of trust negatively impact the JS of the CNAs, whereas increased levels of empowerment increase JS. Implementing strategies to address the needs of CNAs positively impacts society by improving the lives of the workers and increasing CNA retention, thus improving the lives of vulnerable members of society through enhanced quality of care.
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Lui, Yuan Siang. "Developing sustained dual-drug therapy for tendon sports injuries." Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/23739.
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Tendon plays an important role in regulating body locomotion and providing additional stability to the body. However, tendon is susceptible to injuries and the healing process could be devastating along with the several issues, namely adhesion formations, slow healing and failure at fixation sites, which have deferred the success of proper tendon healing via tendon tissue engineering. This dissertation thus aims to create a sustained dual-drug therapy to address these issues. For adhesion formation, naproxen sodium (NPS) has been shown to be able to avoid this symptom through inhibiting inflammation process.
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Berberovic, Adnan, and Alexander Eriksson. "A Multi-Factor Stock Market Model with Regime-Switches, Student's T Margins, and Copula Dependencies." Thesis, Linköpings universitet, Produktionsekonomi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-143715.
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Investors constantly seek information that provides an edge over the market. One of the conventional methods is to find factors which can predict asset returns. In this study we improve the Fama and French Five-Factor model with Regime-Switches, student's t distributions and copula dependencies. We also add price momentum as a sixth factor and add a one-day lag to the factors. The Regime-Switches are obtained from a Hidden Markov Model with conditional Student's t distributions. For the return process we use factor data as input, Student's t distributed residuals, and Student's t copula dependencies. To fit the copulas, we develop a novel approach based on the Expectation-Maximisation algorithm. The results are promising as the quantiles for most of the portfolios show a good fit to the theoretical quantiles. Using a sophisticated Stochastic Programming model, we back-test the predictive power over a 26 year period out-of-sample. Furthermore we analyse the performance of different factors during different market regimes.
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Valtinson, Gale Rene. "A multi-sample confirmatory factor analysis of work-family conflict." Virtual Press, 1998. http://liblink.bsu.edu/uhtbin/catkey/1115719.
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The large-scale entrance of women into the workforce over the past two decades has fundamentally changed the nature of work and family life. This trend has been associated with a constellation of emerging challenges and conflicts in balancing work and family spheres. Gutek, Searle, and Klepa (1991) developed two models for explaining work-family conflict. The Rational Model proposed that workfamily conflict is directly proportionate to the amount of time one spends in work and family activities. The Gender Role Model proposed that work-family conflict is moderated by gender role socialization, in that men are predicted to experience greater work-family conflict when family responsibilities interfere with their career, whereas women are predicted to experience greater conflict when their career interferes with their family responsibilities. To date, models of work-family conflict have been largely derived from White samples, and it has not been established that our models can be generalized across culture. Distinct cultural histories between Black and White women suggest potential differences in how work-family conflict is experienced across ethnicity.The purpose of this study was to test a measure of work-family conflict for invariance across ethnicity. Participants were 111 Black and 119 White, married, middle-income mothers with dependent children who worked outside of the home on a full-time basis. It was hypothesized that Gutek et al.'s (1991) measure of work-family conflict would demonstrate variance across ethnicity. The study further extended Gutek's research by hypothesizing that White women would experience greater work-family conflict when work interfered with family responsibilities than the reverse, and that Black women would be equally sensitive to interference with either domain. Results of a multi-sample confirmatory factor analysis failed to confirm the hypothesis of construct bias or the prediction that White women would be more sensitive to work interference with family life than the reverse. The results of this study supported the prediction that among Black women, there would be no differences in the relationship between family interference with work and work interference with family on total work-family conflict. Limitations of the present study and implications for future research were discussed.Department of Counseling Psychology and Guidance Services
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Hilton, Traci Leigh. "Dual function of TAF1 in basal and activated cyclin D1 transcription /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/6275.
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Lim, Mook Tzeng. "Hydrodynamics of a Cold Model of a Dual Fluidized Bed Gasification Plant." Thesis, University of Canterbury. Chemical and Process Engineering, 2012. http://hdl.handle.net/10092/6287.
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Biomass energy is increasingly used to reduce the dependence on fossil fuels and reduce the impact of greenhouse gas emissions on global warming. Fluidized bed
gasification converts solid biomass into gaseous fuels that can be used for combustion or liquid fuels synthesis. The efficiency of biomass gasification is directly affected by the fluidized bed hydrodynamics. For example, the solids recirculation rate through the system is an important parameter that affects the heat and mass transfer rates. In this study, a cold model of a dual fluidized bed (DFB) biomass gasification plant was designed using scaling laws, and was constructed to investigate the hydrodynamics of
industrial DFBs. A DFB consists of a bubbling fluidized bed (BFB), where biomass is gasified to produce syngas, and a circulating fluidized bed (CFB) where the residues of
gasification are combusted. The investigation was divided into Phase I and II. In Phase I, an operational map was developed for the CFB to define operational boundaries for
steady state operation of the plant. An empirical model was developed to predict the solids mass flow rate out of the CFB riser, which is an empirical function of the exit
opening width, the CFB diameter, and a newly introduced aerodynamic factor. The correlation coefficient, R2 for the empirical function was 0.8327. The aerodynamic
factor accounts for the particle inertia and clustering effects at the exit of the CFB riser. Results from Phase I also showed that increasing the fluidizing velocities increased the solids circulation rate and affected the pressure drop over various points in the CFB plant
due to redistribution of solids with the system. A critical assessment was performed on published correlations found in the literature to determine how accurately they predicted
the hydrodynamics in the CFB riser. By comparing predicted and experimental results, the correlations were found to be inaccurate for the conditions and configuration of the
CFB tested in this study. For example, the solids velocity was not accurately predicted by published correlations due to unaccounted particle clustering effects. The main issue
with the published correlations was a lack of generality, so that the correlations only applied for predicting fluidizing behaviour in the equipment they were developed in. In Phase II, an operational map was developed for the DFB, which incorporated both the CFB and the BFB. Experiments with a binary mixture representing sand and char in an industrial gasifier showed a blocking effect in the connecting chute between the CFB and BFB by the material representing char, which was larger and less dense than the material representing sand. A computational fluid dynamics (CFD) based design tool for modelling the cold model CFB cyclone was developed and validated by comparing the predicted and experimental cyclone pressure drop. The correlation coefficient for the CFD pressure drop prediction was 0.7755. The design tool contained information about the grid resolution and the time step required for modelling the cyclone accurately.
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Malik, Naveed ur Rehman. "Modelling, Analysis, and Control Aspects of a Rotating Power Electronic Brushless Doubly-Fed Induction Generator." Doctoral thesis, KTH, Elektrisk energiomvandling, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-174349.
Full textAbstract:
This thesis deals with the modeling, analysis and control of a novel brushlessgenerator for wind power application. The generator is named as rotatingpower electronic brushless doubly-fed induction machine/generator (RPEBDFIM/G). A great advantage of the RPE-BDFIG is that the slip power recoveryis realized in a brushless manner. This is achieved by introducing an additionalmachine termed as exciter together with the rotating power electronicconverters, which are mounted on the shaft of a DFIG. It is shown that theexciter recovers the slip power in a mechanical manner, and delivers it backto the grid. As a result, slip rings and carbon brushes can be eliminated,increasing the robustness of the system, and reducing the maintenance costsand down-time of the turbine. To begin with, the dynamic model of the RPE-BDFIG is developed andanalyzed. Using the dynamic model, the working principle of the generatoris understood and its operation explained. The analysis is carried out atspeeds, ±20% around the synchronous speed of the generator. Moreover, thedynamics of the generator due to external load-torque disturbances are investigated.Additionally, the steady-state model is also derived and analyzed forthe machine, when operating in motor mode. As a next step, the closed-loop control of the generator is considered indetail. The power and speed control of the two machines of the generator andthe dc-link voltage control is designed using internal model control (IMC)principles. It is found that it is possible to maintain the stability of thegenerator against load-torque disturbances from the turbine and the exciter,at the same time maintain a constant dc-link voltage of the rotor converter.The closed-loop control is also implemented and the operation of the generatorwith the control theory is confirmed through experiments.In the third part of the thesis, the impact of grid faults on the behaviourof the generator is investigated. The operation of the generator and its responseis studied during symmetrical and unsymmetrical faults. An approachto successful ride through of the symmetrical faults is presented, using passiveresistive network (PRN). Moreover, in order to limit the electrical and mechanicaloscillations in the generator during unsymmetrical faults, the dualvector control (DVC) is implemented. It is found that DVC to a certain extentcan be used to safeguard the converter against large oscillations in rotorcurrents. Finally, for completeness of the thesis, a preliminary physical design ofthe rotating power electronic converter has been done in a finite elementsoftware called ANSYS. The thermal footprint and the cooling capability,with estimates of the heatsink and fan sizes, are presented. Besides, another variant of a rotating electronic induction machine whichis based on the Lindmark concept and operating in a single-fed mode is also investigated. It’s steady-state model is developed and verified through experiments.QC 20151006
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Kzam, Aref Kalilo Lima. "Formulação dual em mecânica da fratura utilizando elementos de contorno curvos de ordem qualquer." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/18/18134/tde-03032010-083004/.
Full textAbstract:
Neste trabalho, apresenta-se a formulação do método dos elementos de contorno dual (MECD) aplicada a análise de problemas da Mecânica da Fratura Elástica Linear (MFEL). O objetivo da pesquisa consiste em avaliar o fator de intensidade de tensão (FIT) de sólidos bidimensionais fraturados, por meio de três técnicas distintas, quais são: a técnica da correlação dos deslocamentos, a técnica com base no estado de tensão na extremidade da fratura e a técnica da integral. As análises são realizadas utilizando o código computacional desenvolvido durante a pesquisa, que incorpora as formulações diretas em deslocamento e em força de superfície, do método dos elementos de contorno (MEC), com destaque para a utilização dos elementos de contorno curvos de ordem qualquer. No MECD as equações integrais singulares do tipo O(\'R POT.-1\') e O(\'R POT.-2\') são avaliadas satisfatoriamente com o Método da Subtração de Singularidade (MSS). Dessas integrais resultam termos analíticos, os quais são avaliados por meio do Valor Principal de Cauchy (VPC) e da Parte Finita de Hadamard (PFH). Compara-se o código desenvolvido com as soluções analíticas encontradas na literatura inclusive na análise de sólidos com fraturas predefinidas e para a avaliação do FIT, que produziram bons resultados.This work presents the dual boundary element formulation applied to linear crack problem. The goal of this research is the evaluation of stress intensity factor for two-dimensional crack problem using three different techniques, which are: the technique of correlation of displacements, the technique based on the state of tension at the crack tip and J integral. The analysis is performed using the computational code developed during the research, which incorporates the direct formulations related to displacement and traction boundary element equation. A greater emphasis is given to the use of curved boundary element of any order. In the dual boundary element method the singular integral equations with singular others O(\'R POT.-1\') and O(\'R POT.-2\') are assessed satisfactorily with the application of the singularity subtraction method. The results of these singular integrals are evaluated by the Cauchy Principal Value and the Hadamard Finite Part. The code developed is compared with the analytical solutions found in the literature including the analysis of solids with fractures default and evaluation of stress intensity factor, which produced good results.
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Marzouk, Mounir. "Développement de chargeurs intégrés pour véhicules hybrides plug-in." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT088/document.
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Ces travaux de thèse consistent en la conception et la réalisation d’une chaîne de tractionintégrée pour véhicule hybride plug-in. L’étude s’oriente vers une solution de convertisseur mutualisé,dans l’objectif de partager la traction et les modes chargeurs de batteries, la structure en NPC à 3niveaux est retenue. Le chargeur monophasé se base une topologie de redresseur à MLI monophaséavec trois bras entrelacés, avec l’utilisation des enroulements du moteur pour le filtrage. En chargeurtriphasé nous adaptons la topologie pour réaliser un montage en double boost triphasé. Pour chaqueconfiguration, les passifs sont dimensionnés pour répondre aux contraintes en courant BF et HF. Lecontrôle adopté se base sur les correcteurs résonants. Enfin, un prototype de 5 kW a été réalisé pourvalider les différents modes de l’application.Dans une seconde partie, nous proposons une solution de chargeur isolé sans étage continu auprimaire à double ponts actifs (DAB). La topologie est modélisée au premier harmonique et unecommande assurant l’absorption sinusoïdale est étudiée. Une configuration isolée triphasée permetl’accès aux puissances plus élevées ainsi que la réduction des ondulations de courant BF en sortieThis thesis consists on the design and realization of a plug-in hybrid vehicle integrated tractiondrive supply. The work turns to a solution of a mutualized converter, in the objective to imagine asolution which shared drive and battery chargers modes, the three-level NPC topology has beenretained. The single phase charger is based on an interleaved PWM rectifier, and motor windings areused as smoothing inductors. A double-boost PFC configuration is introduced to ensure the threephasecharger. Passives are sized in each configuration in order to take in account the whole currentconstraints (LF and HF). The PFC behavior is based on the resonant controllers. Then, a 5 kWprototype has been realized to validate the different application modes.In a second part, a single-stage isolated charger based on a Dual-Active-Bridge (DAB) isproposed. The topology is modeled to the fundamental and the PFC control law is studied. A threephaseconfiguration is simulated in order to achieve higher charging powers and to reduce batterycurrent low-frequency ripple
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Hyde, Robert Harry. "Growth and Characterization of Thermoelectric Ba8Ga16Ge30 Type-I Clathrate Thin-Films Deposited by Pulsed Dual-Laser Ablation." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3162.
Full textAbstract:
The on-going interest in thermoelectric (TE) materials, in the form of bulk and films, motivates investigation of materials that exhibit low thermal conductivity and good electrical conductivity. Such materials are phonon-glass electron-crystals (PGEC), and the multi-component type-I clathrate Ba8Ga16Ge30 is in this category. This work reports the first investigation of Ba8Ga16Ge30 films grown by pulsed laser deposition (PLD).
This dissertation details the in-situ growth of polycrystalline type-I clathrate Ba8Ga16Ge30 thin-films by pulsed laser ablation. Films deposited using conventional laser ablation produced films that contained a high density of particulates and exhibited weak crystallinity. In order to produce high quality, polycrystalline, particulate-free films, a dual-laser ablation process was used that combines the pulses of (UV) KrF excimer and (IR) CO2 lasers that are temporally synchronized and spatially overlapped on the target surface. The effect of the laser energy on stoichiometric removal of material and morphology of the target has been investigated. In addition, in-situ time-gated emission spectroscopy and imaging techniques were used to monitor expansion of components in the ablated plumes. Through these investigations, the growth parameters were optimized not only to significantly reduce the particulate density but also to produce large area stoichiometric films. Structure and electrical transport properties of the resultant films were also evaluated. This work provides new insight toward the in-situ growth of complex multi-component structures in thin-film form for potential TE applications.
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Ben, Jazia Abderrahim. "Flexible public private partnerships : a real-option-based optimization approach." Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0176/document.
Full textAbstract:
Les Partenariats Publics Privés (PPPs) peuvent être un outil efficace pour optimiser et moderniser la commande publique dans un contexte où les besoins en investissement public ne cessent d’accroître. Les fréquences importantes de renégociation et les difficultés à estimer correctement les revenus futurs demeurent un défi majeur lors de la structuration financière des PPPs. Ce travail propose d’incorporer des clauses financières flexibles afin de remédier à ce problème. L’approche développée se base sur les théories d’options réelles et d’optimisation multi-objectif. Dans un premier temps, une méthodologie adéquate pour la gestion des risques est développée. La volatilité du projet est déterminée par le biais de la simulation de Monte Carlo et un déflateur stochastique est introduit afin de conduire les différentes valorisations d’options sous la probabilité historique. Ce travail développe dans un second temps, quatre formes de flexibilité qui permettent de réajuster l'équilibre financier du projet, si le revenu est insuffisant. Enfin une approche d’optimisation multi-objectif est développée afin de permettre de visualiser les différents compromis auxquels l’introduction de la flexibilité donne lieuPublic private partnerships can be a solution to the dilemma of how to do more with less available funds that public entities are constantly financing in the last decades. If implemented properly, Public Private Partnerships can contribute to the modernization of public service provision and can constitute efficient vehicles for the delivery of optimal value for money. The high incidence of renegotiation as well as the difficulty of accurately predicting the future demand on the projects is a matter of concern when it comes to the financial structuring of Public Private Partnerships. This work proposes a real-option- based optimization framework to boost the financial viability of the projects. This is done by introducing flexible financial clauses. First, an adequate framework for risk management, where volatility is derived by Monte Carlo simulation and the valuation is made without switching to the risk neutral measure, is presented. Four families of flexible clauses are, afterwards, investigated. Such clauses are triggerred, if the revenue level of the projet is not sufficient to guarnatee its financiel viability. Finally, this work develops a multi-objective optimization approach in order to assess the different trade-offs that the introduction of flexibility leads to. The proposed optimization problem is solved via multi-objective evolutionary algorithms
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Підгурська, Тетяна Вікторівна. "Двосмугові фільтри на діелектричних резонаторах з вищими типами коливань." Doctoral thesis, Київ, 2016. https://ela.kpi.ua/handle/123456789/15382.
Full textAbstract:
У роботі досліджена актуальна задача проектування двосмугових фільтрів на діелектричних резонаторах з вищими типами коливань, що полягає в розробці математичних моделей та нових конструкцій, що забезпечують необхідні електричні параметри за мінімальної кількості елементів зв’язку. Запропоновано використання вищого робочого типу коливання ДР з більш високою добротністю разом із нижчим для побудови двосмугового фільтра; спосіб побудови двосмугових фільтрів на прямокутних ДР, який відрізняється тим, що за рахунок використання видовжених форм ДР з робочими коливаннями TE11δ та TE12δ дозволяє забезпечити приблизно однакові коефіцієнти зв’язку в обох робочих смугах пропускання; спрощений спосіб розрахунку коефіцієнтів зв’язку ДР на основі напруженості магнітного поля; отримано нові аналітичні вирази для розрахунку коефіцієнта взаємного зв'язку між резонаторами; розроблені математичні моделі двосмугових багаторезонаторних фільтрів на «дипольному» та «квадрупольному» типах коливань прямокутних ДР; запропоновано нові конструкції двосмугових багаторезонаторних фільтрів, які відрізняються тим, що мають мінімальну кількість елементів зв'язку.
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Lin, Yen-ting, and 林彥廷. "Study and Implementation of a Dual-mode Power Factor Correct." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/01818393471856188350.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
98
This thesis aims to study a dual-mode boost-type active power factor corrector (PFC), Under light-load condition. the circuit is operated at a Quasi-Resonant (QR) mode or a Boundary Conduction Mode (BCM) to reduce switching losses. Otherwise. the circuit is operated at Continuous Conduction Mode (CCM) under heavy load condition to reduce the device current stresses. Firstly, the operation principles and the zero-voltage switching condition for an ideal power factor correction are analyzed and discussed. Then, two 300W dual-mode boost-type power factor correctors are built and tested to verify the above theoretical analysis, The control circuits of the laboratory prototypes are implemented by using the Texas Instruments chip UC 3854 and external auxiliary circuits, The experimental results are shown to verify the feasibility of the studied schemes. High conversion efficiency can be achieved under light-load conditions and device current stresses can be reduced effectively under heavy-load conditions.
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Zai, Zong-ru, and 蔡宗儒. "Design of Robust Dual Boost Converter Power Factor Correction Circuits." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/77714214170830200229.
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碩士國立中山大學
電機工程學系研究所
99
The traditional AC/DC rectifier usually has the defects of low power factor and serious harmonic distortion and it results in serious pollution to the power system. This thesis proposes active power factor correction technique using a new AC/DC Dual Boost Converter. For power factor correction, inductor current is operated in the continuous conduction mode. First, the converter is analyzed by state space averaging method. Furthermore, we design applicable compensator by frequency analysis to implement a good power factor system. A classical PFC circuit with PI control law has low power factor under light load. In order to overcome problem, the thesis proposes a Dual Boost Converter circuit with robust performance. Comparing with circuits using PFC IC “UC3854”, the proposed system obtains higher power factor under the condition of the same light load.
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Zhan, Zi-zeng, and 詹子增. "Study and Implementation of a Dual-Mode Buck Power Factor Corrector." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/55834889185565944492.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
102
This thesis aims to study a dual-mode buck active power factor corrector (PFC). Under light-load condition, the circuit is operated at boundary conduction mode (BCM) to reduce the switching loss. Otherwise, the circuit is operated at continuous conduction mode (CCM) under heavy-load condition. The peak inductor current is reduced and the conduction loss is less. First, the loss distributions of the PFC at various load levels for both BCM and CCM are analyzed. Therefore, a transition point can be found to switch between the two control modes. A 150-W dual-mode buck PFC prototype is built to verify the circuit analysis and design considerations. The control circuits of the laboratory prototype are implemented by using the STMicroelectronics chip L6561 and additional external circuits. Experimental results show that the studied PFC actually operates under BCM from light-load to half-load conditions to reduce the switching loss, and under CCM at heavy loads to reduce the conduction loss.
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Lin, Chien-Tu, and 林建宇. "Design Optimization of a Dual-Mode Boost-Type Power Factor Corrector." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/68374408369492547693.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
98
The main purpose of this thesis is to propose a new control method for a boost-type power factor corrector (PFC). The presented PFC is operated under boundary conduction mode (BCM) at lighter loads and continuous conduction mode (CCM) at heavier loads. The MOSFET is turned on with zero current, and thus zero switching loss, when the PFC is operated under BCM. However, the peak inductor current is higher and therefore the conduction loss increases as the load gets heavier. On the other hand, the output diode has reverse recovery phenomenon that results in a higher switching loss when the PFC is operated under CCM. This problem is more obvious as the load decreases. Nevertheless, under CCM, the peak inductor current is smaller and the conduction losses are smaller, too. A novel dual-mode PFC controller is proposed in this thesis, with BCM operations at light loads and CCM operations at heavy loads, to take the advantages and improve the disadvantages of both modes. First the loss distributions of the PFC at various load levels for both BCM and CCM are analyzed. Therefore, a most suitable transition point can be found to switch between the two control modes. A 300-W dual-mode boost-type PFC prototype is built to verify the circuit analysis and design considerations. Experimental results show that the studied PFC actually operates under BCM at light loads to reduce the switching loss, and under CCM at heavy loads to reduce the conduction loss.
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Hsieh, Shi-Yuan, and 謝時淵. "A High-Power-Factor AC/DC Converter with Dual Flyback Conversion Circuits." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/73t6qy.
Full textAbstract:
碩士義守大學
電機工程學系
104
This thesis proposes a high power-factor AC-DC converter with two flyback conversion circuits. The interleaved flyback converters adopt two power MOSFETs as the active switches. With no need to use any auxiliary components and snubber circuit, both active switches can operate at zero-voltage switching on (ZVS) by freewheeling the inductor current through the body diode of the MOSFET. Operating active switches at ZVS can effectively decrease the switching losses, and hence improve the circuit efficiency. As comparing the proposed interleaved circuit with traditional one, the former is with the advantage of lower current and voltage ripples. It helps to decrease the current and voltage stresses on the circuit components. Besides, the circuit reliability can be improved. The detail circuit operation and analysis are provided. A prototype circuit of a 200-W converter was built and tested. The experimental results show that the switching losses can iii be effectively reduced by operating the active switches at ZVS. The proposed circuit can achieve nearly unity power factor and the measured circuit efficiency is 93.25%.
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Yang, Cheng-yan, and 楊政諺. "Study and Implementation of a Dual-Mode Push-Pull Boost Power Factor Corrector." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/2r8t77.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
99
The operations of the proposed dual-mode push-pull boost power factor corrector can be under either quasi-resonant (QR) mode or discontinuous conduction mode (DCM). For QR mode operation, the valley-switching on the switch and zero-current-switching (ZCS) of the output diode can reduce the switching losses and improve the conversion efficiency. On the other hand, the DCM operation features fixed switching frequency, ZCS of the output diode, natural PFC function, simplified control methodology and EMI filter design. Circuit principles and design procedures are presented and verified by the simulations and experimental results. A prototype is then implemented with universal line voltage, a 380 V output DC voltage 380 V and 300 W power rating. The minimum efficiencies at line voltages of 100Vac and 220Vac are 94.4% and 96.7%, respectively.
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Kauer, Michaela. "Identification as Determining Factor of Technology Acceptance for Hedonic and Dual Use Products." Phd thesis, 2012. https://tuprints.ulb.tu-darmstadt.de/3107/1/DissertationMichaelaKauer.pdf.
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The rising importance of hedonic and dual use products is well noticed in literature, but up until now not appropriately addressed in technology acceptance research. Financial losses and dissatisfaction are the outcomes of this omission. Therefore, this thesis addressed this area by investigating three main research points: re-defining technology acceptance for hedonic and dual use products, developing and validating a model which predicts and ex-plains technology acceptance better than existing models, and investigating the role of the usage mode for technology acceptance.
First, technology acceptance was re-defined as positive attitude towards a certain technology in combination with the intention to use the technology. Then, different technol-ogy acceptance models were investigated and judged according to their appropriateness for explaining technology acceptance in the context of hedonic and dual use products. The re-vised TAM was chosen, because it was already used in the context of hedonic systems and proofed to be better than models that do not integrate hedonic qualities. It was aimed for the improvement of this model due to the still low explanatory power of the model. This im-provement was found by investigating different needs as basis for positive emotions during the interaction with products. Stimulation, competence, and identification were identified as most promising needs. Those needs were already part of the hedonic/pragmatic model of user experience, which led to the decision to merge both models into one combined model. The resulting model was called Balanced TAM.
Three user studies were conducted to test the validity and explanatory power of the model. It was shown that Balanced TAM explains significantly more variance of technology acceptance than revised TAM for hedonic and dual use products. Additionally, it did not per-form worse for utilitarian products. The results and the methodological approach were dis-cussed and open points identified. Those points were addressed in the future work section at the end of the thesis.
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WU, JIA-JHOU, and 吳家州. "The role of customer participation in IT services relationship maintenance – a dual-factor perspective." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/qr62me.
Full textAbstract:
博士國立臺灣科技大學
企業管理系
105
The study investigates the influences of customer participation on relationship maintenance by adopting the two-factor model, and identifies potential antecedents of customer participation. Empirical data was collected from 126 firms which receive information technology (IT) services in Taiwan. The results of this study showed that customer participation positively influences customer loyalty through the following mechanisms: 1) service quality and satisfaction, and 2) switching costs. Additionally, IT capabilities, organizational compatibility, and role clarity are positively related to customer participation. The findings can serve as a guideline for IT service firms to promote customer participation and for general enterprises to select IT service firms.
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Excell, Peter S., and Z. M. Hejazi. "Compact Superconducting Dual-Log Spiral Resonator with High Q-Factor and Low Power Dependence." 2002. http://hdl.handle.net/10454/3260.
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NoA new dual-log spiral geometry is proposed for microstrip resonators, offering substantial advantages in performance and size reduction at subgigahertz frequencies when realized in superconducting materials. The spiral is logarithmic in line spacing and width such that the width of the spiral line increases smoothly with the increase of the current density, reaching its maximum where the current density is maximum (in its center for ¿/2 resonators). Preliminary results of such a logarithmic ten-turn (2 × 5 turns) spiral, realized with double-sided YBCO thin film, showed a Q.-factor seven times higher than that of a single ten-turn uniform spiral made of YBCO thin film and 64 times higher than a copper counterpart. The insertion loss of the YBCO dual log-spiral has a high degree of independence of the input power in comparison with a uniform Archimedian spiral, increasing by only 2.5% for a 30-dBm increase of the input power, compared with nearly 31% for the uniform spiral. A simple approximate method, developed for prediction of the resonant frequency of the new resonators, shows a good agreement with the test results.
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Huang, Shr-Hau, and 黃世豪. "The design and implementation of a 250W dual-switch forward converter with power-factor-correction." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/81182492745866693463.
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CHEN, GUANG-JUNE, and 陳廣駿. "A High-Power-Factor Lithium Battery Charger with Dual Bridgeless Single-Stage Resonant Conversion Circuits." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/bp44xx.
Full textAbstract:
碩士國立虎尾科技大學
電機工程系碩士班
106
This thesis proposes a high-efficiency and high-power factor lithium battery charger which integrates a bridgeless boost-type power-factor-correction converter and a full bridge LLC resonant circuit to comprise a single-stage topology. The proposed lithium battery charger will be featured with high-efficiency, high power-factor and reduced current and voltage stresses on components by introducing a pair of converters using series-input and parallel-output mechanism. By merging the bridgeless power-factor-correction technique and the full bridge LLC resonant circuit into a single-stage structure, the proposed battery charger achieves the advantages of: (1) bridgeless structure reducing circuit losses;(2) resonant technique usage furnishing power switches with zero-voltage-switching and output stage diodes with zero-current-switching and enhancing the circuit efficiency; (3) constant current and voltage charging power regulation with frequency modulation scheme simplifying the trigger circuit complexity and widening the charging power range; (4) series-input and parallel-output dual converters topology sharing current and voltage stresses and reducing the component rating; (5) paired interleaved power-factor-correction operation sharing current loading and thus increasing charging battery size. Hopefully, this project aims at accomplishing a high power lithium battery charger with high power-factor, high-efficiency, low component rating, electric isolation, zero-voltage-switching and wide charging power range.