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Bias and Precision of the Squared Canonical Correlation Coefficient under Nonnormal Data ConditionsLeach, Lesley Ann Freeny 08 1900 (has links)
This dissertation: (a) investigated the degree to which the squared canonical correlation coefficient is biased in multivariate nonnormal distributions and (b) identified formulae that adjust the squared canonical correlation coefficient (Rc2) such that it most closely approximates the true population effect under normal and nonnormal data conditions. Five conditions were manipulated in a fully-crossed design to determine the degree of bias associated with Rc2:
distribution shape, variable sets, sample size to variable ratios, and within- and between-set correlations.
Very few of the condition combinations produced acceptable amounts of bias in Rc2, but those that did were all found with first function results. The sample size to variable ratio (n:v)was determined to have the greatest impact on the bias associated with the Rc2 for the first, second, and third functions. The variable set condition also affected the accuracy of Rc2, but for the second and third functions only. The kurtosis levels of the marginal distributions (b2), and the
between- and within-set correlations demonstrated little or no impact on the bias associated with Rc2. Therefore, it is recommended that researchers use n:v ratios of at least 10:1 in canonical analyses, although greater n:v ratios have the potential to produce even less bias. Furthermore,because it was determined that b2 did not impact the accuracy of Rc2, one can be somewhat confident that, with marginal distributions possessing homogenous kurtosis levels ranging
anywhere from -1 to 8, Rc2 will likely be as accurate as that resulting from a normal distribution.
Because the majority of Rc2 estimates were extremely biased, it is recommended that all Rc2 effects, regardless of which function from which they result, be adjusted using an appropriate adjustment formula. If no rationale exists for the use of another formula, the Rozeboom-2 would likely be a safe choice given that it produced the greatest number of unbiased Rc2 estimates for the greatest number of condition combinations in this study.
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Therapeutic Assessment as Preparation for PsychotherapyVance, Jeffrey Michael 08 1900 (has links)
This study examined the impact therapeutic assessment (TA) had on participants recruited from the UNT Psychology Clinic's waiting list. Using a pretest-posttest design, participants completed measures prior to and following their assessment. UNT Psychology Clinic archive data was used to compare this sample to clients who received traditional information gathering assessments with implicit measures, those receiving assessments relying on only self-report measures, and those who did not receive an assessment before beginning psychotherapy. The findings of this study vary based on the criteria being examined. Due to the small sample in the experimental group, no statistical significance was found through null hypothesis testing. However, the TA group's scores on the Outcome Questionnaire – 45 (OQ) and the Working Alliance Inventory (WAI) indicated better outcomes than those without a TA, with large effect sizes. Furthermore, those who received a TA were more likely than those without a TA to score below the clinically significant cutoff levels on the OQ. The study raises issues for consideration in what is deemed "effective" in therapeutic efficacy research.
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A Permutation-Based Confidence Distribution for Rare-Event Meta-AnalysisAndersen, Travis 18 April 2022 (has links)
Confidence distributions (CDs), which provide evidence across all levels of significance, are receiving increasing attention, especially in meta-analysis. Meta-analyses allow independent study results to be combined to produce one overall conclusion and are particularly useful in public health and medicine. For studies with binary outcomes that are rare, many traditional meta-analysis methods often fail (Sutton et al. 2002; Efthimiou 2018; Liu et al. 2018; Liu 2019; Hunter and Schmidt 2000; Kontopantelis et al. 2013). Zabriskie et al. (2021b) develop a permutation-based method to analyze such data when study treatment effects vary beyond what is expected by chance. In this work, we prove that this method can be considered a CD. Additionally, we develop two new metrics to assess a CD's relative performance.
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Examining Treatment Effects for Single-Case ABAB Designs through Sensitivity AnalysesCrumbacher, Christine A. 10 June 2013 (has links)
No description available.
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Load Balancing Parallel Explicit State Model CheckingKumar, Rahul 28 June 2004 (has links) (PDF)
This research first identifies some of the key concerns about the techniques and algorithms developed for distributed and parallel model checking; specifically, the inherent problem with load balancing and large queue sizes resultant in a static partition algorithm. This research then presents a load balancing algorithm to improve the run time performance in distributed model checking, reduce maximum queue size, and reduce the number of states expanded before error discovery. The load balancing algorithm is based on Generalized Dimension Exchange (GDE). This research presents an empirical analysis of the GDE based load balancing algorithm on three different supercomputing architectures---distributed memory clusters, Networks of Workstations (NOW) and shared memory machines. The analysis shows increased speedup, lower maximum queue sizes and fewer total states explored before error discovery on each of the architectures. Finally, this research presents a study of the communication overhead incurred by using the load balancing algorithm, which although significant, does not offset performance gains.
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An Experimental Investigation of the Hardenabilities Tensile and Fracture Properties of Powdered Metal SteelsTallon, Paul January 2018 (has links)
Powder metallurgy (PM) steel is produced by near net shape manufacturing, which is used to fabricate alloy steels for many purposes. Designing new powder metal steels that can form a significant fraction of martensite relies on hardenability calculations developed for wrought steels. These proven tools are built upon assumptions for wrought steels that do not hold true for PM steels. One assumption is that the alloying elements are homogenized throughout the material. In admixed powder blends that are industrially sintered this is not the case. Using prealloyed powder is a solution to this issue, yet it places restrictions on alloy design and compressibility. There are tools available to computationally optimize diffusion problems, yet the complexity during the sintering of PM steel is such that a robust model has yet been produced. It is intuitive that with smaller particles of Fe sintering time can be reduced. A direct experimental investigation linking Fe-powders’ sizes and hardenability on Fe-C-Cr-Mn-Mo-Ni PM steel was subject to microstructure analysis and mechanical properties (Jominy test) for comparative analysis.
Another assumption that is made for wrought steel is a consistent density of 7.87g/cm3. This is not the case for PM steel as the press and sinter method produces pores, decreasing the density. This directly affects the thermal conductivity and phase transformation of the steel. In an effort to understand how these differences affect Grossmann’s predictions of hardenability, a direct experimental investigation linking the density to hardenability was launched on prealloyed FL-4605 and FL-4605+2%Cu. Specifically the Jominy test was completed on a range of densities, as well as compared to software predictions.
The chemical variations in admixed and sintered PM steel produce a unique system where one TTT diagram cannot predict the entire final microstructure. PM steel such as this is observed in industry, and can be created through incorporating larger Fe-particles such that less alloying constituents have a chance to fully alloy these regions. Since the large particles will not have the chance to be alloyed, they will not have the ability to form martensite. Since the regions between large particles will be alloyed, martensite will form, creating a hard matrix surrounding softer particles. This structure is characteristic of a metal matrix composite (MMC), and therefore should be treated as such. There are methods of MMC design that involve numerical methods of predicting strength and toughness. These methods, along with experimental data (tensile and Charpy testing) of Fe-C-Cr-Mn-Mo-Ni PM steels with ranging volume fractions of pearlitic inclusions were compared. / Thesis / Master of Applied Science (MASc)
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Exkluderande mode? : En fallstudie om avsaknaden av stora klädstorlekar och varumärkesidentitet hos fyra svenska modebolag.SALEH, SOFIA January 2015 (has links)
Purpose: The purpose of this paper to analyze whether there is any connection between the brand identity of four Swedish fashion companies and their lack of a comprehensive size range for women. Both primary and secondary data has been the basis of this paper. A theoretical framework using brand identity and STP models was created with the help of secondary data. Limitations: The choice to investigate four case companies limits the ability to generalize the results. In order to reach a comprehensive industry understanding, additional case companies would be needed. Method: The study is based on deductive approach with qualitative research. In the deductive approach, the researcher uses existing theoretical models within brand identity and the STP process to help analyze the empirical data and draw conclusions. Results: The results show that the cost of producing a narrower range of clothing is the main reason why the companies do not offer larger clothing sizes for women. The second factor, according to three of the four companies, is that it is technically difficulty to simply increase the size of clothing, and would require specialist knowledge to adapt the designs. Two of the four companies see some connection between brand identity and the lack of a comprehensive size range, but view this not as a decisive factor but rather, an influencing factor. / Syfte: Syftet med uppsatsen är att utifrån fyra svenska modebolags perspektiv analysera om det finns något samband mellan deras varumärkesidentitet och dess avsaknad av heltäckande storleksutbud för kvinnor. Både primär och sekundär data har legat till grund för denna studie. Med hjälp av sekundära data har den teoretiska referensramen, som använder varumärkesidentitet och STP-modellen, skapats. Avgränsning: Valet att undersöka fyra fallföretag utgör ingen generaliserbarhet. För det behövs undersökning av ytterligare flera fallföretag genomföras. På så sätt kan en generell branschförståelse fås. Metod: Studien utgår från en deduktiv ansats med en kvalitativ forskningsmetod. I den deduktiva ansatsen kommer forskaren använda sig av befintliga teoretiska modeller inom varumärkesidentitet och STP processen som hjälp för att analysera data i empirin och dra slutsatser. Resultat: För de undersökta bolagen visar resultatet att kostnaden för produktion av mindre klädvolymer är den främsta anledningen till det avvägande man gjort om att inte erbjuda större klädstorlekar till kvinnor. Den andra faktorn är enligt tre av fyra bolag att man ser en svårighet designtekniskt att bara öka upp storleken vilket gör att det krävs specialistkunskap för att hantera större kläddesign. Sen ser två av fyra bolag ett visst samband mellan varumärkesidentiteten och det bristande heltäckande storleksutbudet, inte som en avgörande faktor men som en påverkande faktor.
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Development of standardized sizing systems for the South African children’s wear marketVan Huyssteen, S. 04 1900 (has links)
Thesis (DSc (Consumer Science)--University of Stellenbosch, 2006. / 326 leaves on CD format, preliminary i-xix pages and numbered pages 1-210. Includes bibliography, list of tables, figures and appendixes. / ENGLISH ABSTRACT: This research focused on the need of the children’s wear industry in South Africa for sizing systems based on accurate and current body measurement tables developed from the actual measurements of children. The broad objective of this study was to develop standardised measuring methodologies and techniques which would be relevant to the subsequent development of reliable, accurate and comprehensive body measurement tables. These tables could then be implemented as a basis for the development of new sizing systems, as well as new, improved and authentic fit dummy ranges. The literature study served as a point of departure for the planning and execution of the empirical study, focusing on sizing and size designation systems. The study population comprised children representative of three categories, namely age (2 to 14 years), gender (boys and girls) and sector (Black and Non-Black) categories. A convenience sample was selected, representing children from two geographical areas (Western Cape and Gauteng). The empirical study has a three phase structure. The first pilot study aimed at developing standardised measuring equipment, as well as the methodologies and properly recorded guidelines for their implementation. The specific standards according to which subjects were measured and the strict quality control measures implemented to ensure the validity, reliability and accuracy of recorded data, were confirmed during the second pilot study. Based on this, the final study was executed following the guidelines as recorded in the Field Worker Manual. The statistical analysis was done after data capturing during which the data sets were first cleaned up. Secondly, the key measurements for use as a basis for the development of the sizing systems were identified. Based on these, body measurement tables were compiled and age of gender split and growth patterns were analysed for fit dummy prototype development. The new size designation system developed for children’s clothing was successfully implemented as a multi-indicator system, linking height ranges with both age ranges and numerical size indicators. The development of the subsequent new and improved fit dummy prototypes was based on measurements within minimum and maximum values of the body measurements, in order to facilitate the construction of these three-dimensional bodies. It was also possible to develop complete body measurement tables with accurate, and notably irregular, increments between sizes as well as to determine specific growth patterns and separate growth spurts for both boys and girls. This study made new and original as well as more detailed and correct information available concerning the size and shape of the typical South African children’s wear consumer. Using the information contained in the new height based sizing system, retailers have been able to develop a proper set of grade rules for application in product development. The identification and demarcation of important body landmarks facilitated pattern drafting, garment development and fit assessments, resulting in an improved product offering for the typical South African children’s wear consumer. Recommendations regarding further research were formulated, such as comparing the study population categories, namely gender, age and sector. Implications for retailers, inter alia that each retail company could choose how to implement the new height based sizing system and the specific size designation system most suitably for their own consumers and internal systems. The standards set and methodologies implemented in this survey were an improvement on the sizing and fit of children’s wear in the context of South African manufacturers, retailers and consumers. / AFRIKAANSE OPSOMMING: Hierdie navorsing fokus op die behoefte van die Suid-Afrikaanse kinderklerekleinhandelbedryf aan ‘n sisteem van kleregroottes, gebaseer op akkurate en huidige liggaamsmate-tabelle wat ontwikkel is van die werklike mates van kinders. Die oorkoepelende doelstelling van hierdie studie was om gestandaardiseerde meetmetodologieë en -tegnieke te ontwikkel wat relevant is vir die daarstelling van betroubare, akkurate en omvattende liggaamsmate-tabelle, wat dan gebruik kan word as basis vir die nuwe kleregroottesisteem, sowel as om nuwe, verbeterde en oorspronklike figuurmodelreekse te ontwikkel. Die literatuurstudie het gedien as vertrekpunt vir die beplanning en uitvoering van die empiriese studie met die fokus op kleregroottesisteme en kleregrootteaanwysingsisteme. Die kinders in die studiepopulasie het drie kategorieë verteenwoordig: ouderdom (2 tot 14 jaar), geslag (seuns en meisies) en sektor (Swart en Nie-Swart). ‘n Gerieflikheidsteekproef is uit twee geografiese areas (Wes-Kaap en Gauteng) gekies. Die empiriese studie het ‘n drie-fase-struktuur. Die eerste loodsstudie het ten doel gehad om gestandaardiseerde meettoerusting, meetmetodologieë en behoorlik aangetekende implementeringsriglyne daar te stel. Die spesifieke standaarde waarvolgens die proefpersone gemeet is en die implementering van streng kwaliteitbeheermaatreëls wat geldige, betroubare en akkuraat vasgelegde data verseker, is tydens die tweede loodsstudie bevestig. Die finale studie is gebaseer op en uitgevoer volgens die riglyne soos uiteengesit in die Field Worker Manual. Die statistiese analise is gedoen nadat die data vasgelê en skoongemaak is. Vervolgens is sleutelmates geïdentifiseer wat as basis vir die ontwikkeling van kleregroottesisteme kan dien. Volledige liggaamsmate-tabelle is daarna ontwikkel. Die identifisering van die geslagverdelingsouderdom, sowel as die analisering van groeipatrone vir die ontwikkeling van figuurmodelle, is hierop gebaseer. Die nuwe klere-aanwysingsisteme wat ontwikkel is vir kinderklere is suksesvol geïmplementeer as ‘n veelvoudige aanwysingsisteem wat liggaamslengtereekse met ouderdomsreekse en numeriese grootte-aanwysers koppel. Die nuwe en verbeterde figuurmodel-prototipes wat vervolgens ontwikkel is, is gebaseer op minimum en maksimum waardes van die liggaamsmates ten einde die konstruksie van die driedimensionele figure te vergemaklik. Daarbenewens was dit moontlik om volledige liggaamsmate-tabelle met akkurate en opmerklik ongelyke inkremente tussen groottes daar te stel, sowel as om die spesifieke groeipatrone en afsonderlike groeitoenames vir beide seuns en meises te bepaal. Die studie het nuwe en oorspronklike, sowel as meer gedetailleerde en korrekte inligting ten opsigte van die grootte en vorm van die tipiese Suid-Afrikaanse kinderklereverbruiker beskikbaar gestel. Met hierdie nuwe kennis van die liggaamslengte-gebaseerde kleregroottesisteem, is dit nou vir kleinhandelaars moontlik om ‘n volledige stel graderingsreëls daar te stel en in produkontwikkeling toe te pas. Die identifikasie en afbakening van belangrike liggaamsbakens vergemaklik patroon- en klereontwikkeling sowel as die evaluering van die mate waarin dit pas; dit waarborg ‘n verbeterde produk vir die tipiese Suid-Afrikaanse kinderklereverbruiker. Aanbevelings vir verdere navorsing is gemaak, soos ‘n vergelyking van die studiepopulasiekategorieë, naamlik geslag, ouderdom en sektor. Die implikasies vir kleinhandelaars is onder meer dat elke kleinhandelaar kan kies hoe om hierdie nuwe liggaamslengte-gebaseerde kleregroottesisteem te implementer en watter die mees geskikte kleregrootte-aanwysingsisteem vir hul verbruikers en interne sisteme sal wees. Die standaarde wat vir hierdie studie gestel is, sowel as die metodologieë wat geïmplementeer is, is ‘n aansienlike verbetering op die groottes en pas van kinderklere binne die konteks van die Suid-Afrikaanse vervaardigers, kleinhandelaars en verbruikers.
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Electrostatics of the Binding and Bending of Lipid Bilayers: Charge-Correlation Forces and Preferred CurvaturesLi, Yang January 2004 (has links)
Lipid bilayers are key components of biomembranes; they are self-assembled two-dimensional structures, primarily serving as barriers to the leakage of cell's contents. Lipid bilayers are typically charged in aqueous solution and may electrostatically interact with each other and with their environment. In this work, we investigate electrostatics of charged lipid bilayers with the main focus on the binding and bending of the bilayers.
We first present a theoretical approach to charge-correlation attractions between like-charged lipid bilayers with neutralizing counterions assumed to be localized to the bilayer surface. In particular, we study the effect of nonzero ionic sizes on the attraction by treating the bilayer charges (both backbone charges and localized counterions) as forming a two-dimensional ionic fluid of hard spheres of the same diameter <i>D</i>. Using a two-dimensional Debye-H??ckel approach to this system, we examine how ion sizes influence the attraction. We find that the attraction gets stronger as surface charge densities or counterion valency increase, consistent with long-standing observations. Our results also indicate non-trivial dependence of the attraction on separations <i>h</i>: The attraction is enhanced by ion sizes for <i>h</i> ranges of physical interest, while it crosses over to the known <i>D</i>-independent universal behavior as <i>h</i> → ∞; it remains finite as <i>h</i> → 0, as expected for a system of finite-sized ions.
We also study the preferred curvature of an asymmetrically charged bilayer, in which the inner leaflet is negatively charged, while the outer one is neutral. In particular, we calculate the relaxed area difference Δ <i>A</i><sub>0</sub> and the spontaneous curvature <i>C</i><sub>0</sub> of the bilayer. We find Δ <i>A</i><sub>0</sub> and <i>C</i><sub>0</sub> are determined by the balance of a few distinct contributions: net charge repulsions, charge correlations, and the entropy associated with counterion release from the bilayer. The entropic effect is dominant for weakly charged surfaces in the presence of monovalent counterions only and tends to expand the inner leaflet, leading to negative Δ <i>A</i><sub>0</sub> and <i>C</i><sub>0</sub>. In the presence of even a small concentration of divalent counterions, however, charge correlations counterbalance the entropic effect and shrink the inner leaflet, leading to positive Δ <i>A</i><sub>0</sub> and <i>C</i><sub>0</sub>. We outline biological implications of our results.
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Barreiras na captação de recursos: um estudo a respeito das barreiras de investimento para o investidor em instituições financeiras de pequeno e médio portesAngelin, Flávio Antônio 20 May 2008 (has links)
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Previous issue date: 2008-05-20 / This paper s aim is to unearth the barriers raised by individual investors when facing
the decision to invest their resources with small and medium sized banks. A thorough
sampling amongst potential investors followed by an in depth analysis of the effective
barriers which inhibit them when deciding to invest in the financial markets, was
undertaken. To substantiate the results obtained, suppositions utilized by the
potential investors, as arguments for theoretical barriers against investing with small
and medium sized banks. The sampling data analysis shows that the first barrier is
the non-acquaintance from the investors about small and medium sized banks,
caused by the lack of information about these, contributing to the low credibility
perception. Both the results obtained through the studies added to the suppositions
voiced by the potential investors, can serve as help in formulating the
aforementioned banks marketing studies and strategies, serving also to implement
actions towards increasing their clientele by the elimination of said barriers. As a
corollary more resources will be originated in order to generate a sustainable growth
in their loan portfolios / Este trabalho objetiva investigar as barreiras encontradas pelos investidores,
pessoas físicas, quando da decisão de aplicarem seus recursos em instituições
financeiras de pequeno e médio portes. Foi realizada uma pesquisa de campo com
potenciais investidores e para se obter um resultado mais fundamentado, partiu-se
de alguns pressupostos teóricos observados com os investidores no mercado
financeiro, como prováveis barreiras para investirem em instituições financeiras de
pequeno e médio portes. Como vista na compilação dos dados da pesquisa, a
barreira que apareceu em primeiro lugar foi a do desconhecimento que os
investidores têm em relação às instituições financeiras de pequeno e médio portes,
ocasionado pela falta de informações, o que contribui para a pouca credibilidade.
Tanto os resultados como as proposições poderão fornecer a estas instituições
subsídios para as análises mercadológicas e implementação de ações direcionadas
a vencer estas barreiras, ampliando sua base de clientes, captando mais recursos e,
conseqüentemente, propiciando um crescimento mais sustentável de suas carteiras
de empréstimos
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