Objective: This work consisted of three research projects bridged by their focus on a multivariate assessment of executive functions in research and practice: (a) a systematic review and re-analysis of latent variable studies on executive function test batteries, (b) a confirmatory factor analysis (CFA) of the Delis-Kaplan Executive Function System (D-KEFS), the most commonly administered executive function test battery in clinical practice, and (c) the derivation of multivariate base rates for the D-KEFS, offering a psychometric resource with direct applications to clinical practice. Method: Systematic review. The systematic review identified 45 eligible samples (N=9,498 participants, mean age range: 3.01-74.40 years-old) and 21 correlation matrices eligible for re-analysis, comparing seven competing models including the most commonly evaluated factors: updating/working memory, inhibition, and shifting. Model results were summarized based on the mean percent accepted (i.e., mean rate at which models both properly converged and met fit thresholds: CFI≥.90/RMSEA≤.08). CFA. Using adults from the D-KEFS normative sample (N=425; 20-49 years-old), eight alternative measurement models were evaluated for a subset of D-KEFS tests. Factors from the accepted measurement model predicted three tests measuring constructs less often evaluated in the executive function literature: abstraction, reasoning, and problem solving. Base rates. The frequency of low scores occurring among the D-KEFS normative sample (N=1,050; 16-89 years-old) was calculated for the full D-KEFS and two brief batteries using stratifications for age, education, and intelligence. Results: Systematic review. The most often accepted models varied by age (preschool=one/two-factor; school-age=two/three-factor; adolescent/adult=three/nested-factor; older adult=two/three-factor), and most frequently included updating/working memory, inhibition, and shifting factors. The nested-factor and three-factor models were accepted most often and at similar rates among adult samples: 33-34% and 25-32%, respectively. No model was accepted most often for child/adolescent samples, but those with shifting differentiated garnered less support. CFA. A three-factor model including inhibition, shifting, and fluency fit the data well (CFI=0.938; RMSEA=0.047), although a two-factor model merging shifting/fluency fit similarly well (CFI=0.929; RMSEA=0.048). A bifactor model fit best (CFI=0.977; RMSEA=0.032), but rarely converged. Shifting best predicted tests of reasoning, abstraction, and problem solving (p<0.05; R2=0.246-0.408). Base rates. Low scores, based on commonly used clinical cutoffs, occurred frequently among healthy adults. For a three-test, four-test, and full D-KEFS battery, 62.8%, 71.8%, and 82.6% obtained ≥1 score(s) ≤16th percentile, respectively, and 36.1%, 42.0%, 50.7%, obtained ≥1 score(s) ≤5th percentile, respectively. The frequency of low scores increased with lower intelligence and fewer years of education. Discussion: The systematic review effort did not identify a definitive model of executive functions for either adults or children/adolescents, demonstrating the continued need to re-evaluate the conceptualization and measurement of this construct in future research. The D-KEFS CFA offers some evidence of clinical measures capturing theoretical constructs, but is not directly translatable into clinical practice; while the multivariate base rates are useful to clinicians, but do not bridge theory and assessment. This research reaffirms the elusive nature of executive functions in both research and clinical spheres, and represents a step forward in an enduring scientific process towards a true understanding of this mysterious construct. / Graduate / 2018-07-24

Magister Artium - MA / Recent advancements in child well-being research have shown an increased interest in the importance of subjective well-being. The development of instruments and scales to measure subjective well-being among children and adolescents is in its infancy. Furthermore, there are few existing cross-cultural studies with child and adolescent populations. Validation of existing measures and cross-cultural comparisons has been identified by a number of researchers as critical in contributing to the international dialogue. In the current study, two measures of subjective well-being (Student Life Satisfaction Scale and Personal Well-Being Index-School Children) are tested among a sample of children in the Western Cape region of South Africa. Noting the diversity of experience between children from different socio-economic status groups in South Africa, the study further aims to determine the extent to which the measures are comparable across socio-economic status groups. Data from the Children’s World Survey were used; and includes a sample of 1004 children randomly selected from 15 schools within the Cape Town Metropole. Confirmatory factor analysis was used to test the overall fit structure and multi-group factor analysis, with Scalar and Metric invariance constraints. The results show appropriate fit structure for the overall model, with Scalar and Metric factor invariance tenable across socio-economic status groups. The overall findings suggest that the two measures are appropriate for use with children from low and medium socio-economic status groups in the Western Cape province of South Africa.

>Magister Scientiae - MSc / This study is focused on the Akanani prospect area, approximately 25 km north-west of the town of Mokopane, Limpopo Province where exploration geologists at the study area have classified the ‘pyroxenitic’ units into P1, P2, P3 and P4 units upward in order of succession with height based on their textures, mineralogy and colour. The primary aim of this study is to distinguish the distinctive geochemical and mineralogical characteristics that can be used to identify each unit (P1 to P4) and in so doing create major geochemical, petrographic and mineralogical variables that will help or facilitate the exploration for and recovery of PGE and BMS mineralisation. Geochemical and mineralogical variation studies were carried out on the cores from ZF044, ZF045, ZF048, ZF057, ZF078, ZF082 and M0023, located in the Platreef at the Akanani Prospect area on the farms Moordkopje 813LR and Zwartfontein 814LR. Using a combination of various multivariate statistical techniques (factor, cluster and discriminant analysis) and mineralogical studies (CIPW norm, microprobe analysis, petrography), the outcomes of the study have demonstrated that the Platreef at Akanani comprise at least four lithological units i.e. the basal pyroxenite portion referred to as the P1 unit comprises chromitite, pyroxenites and feldspathic pyroxenites with associated Cr, TiO2, chromite, pyroxenes, hematite and Fe2O3, the mineralized section of the P2 unit is characterized by harzburgite, serpentinized harzburgite and in places orthopyroxenites are present consistent with high MgO and LOI contents, the feldspathic portion referred here as the P3 unit is characterized by a feldspathic pyroxenite containing higher Al2O3, Na2O, K2O, albite, hypersthene and SiO2 and the top most portion of the P4 unit comprising CaO, Diopside, ilmenite, anorthite, apatite and P2O5 that can be interpreted to have formed by three separate magma pulses. Considering the possibility that the P4 unit is a hybrid melt of assimilated Platreef that interacted with intruding Main Zone magma, this reduces the number of magma pulses to two. The classification of P1, P2, P3 and P4 units of the Platreef at Akanani shows that the criteria used by mining personnel to classify the four lithological units is not definitive and therefore are not highly reliable. Although various multivariate statistical techniques were employed relatively similar elemental associations were obtained highlighiting the importance of this approach. The strongly positive correlation between sulphides, PGEs and chromite at Akanani is consistent with an orthomagmatic deposit that had been disturbed by significant hydrothermal activity, while in places a good BMS-PGE relationship is commonly associated with the main chromitite stringers in P1. Mineral and whole rock compositions of silicate rocks highlight the strongly magnesian nature of the ultramafic P2 unit. Mineral chemistry studies of chromite, orthopyroxene, olivine, clinopyroxene and plagioclase are consistent with the multi- emplacement model. Convective exchange resulted in the enrichment of iron at the bottom of the stagnant chamber, while incompatible elements migrated upwards consistent with iron depletion with stratigraphic height. Injection of P1 magma and subsequent mixing with country rocks gave rise to the formation of chromitites and addition of plagioclase component to the intruding magma. A normal fractionation trend is suggested between P2 and P3 consistent with enrichment of MgO in P2 and enrichment of Al2O3, Na2O, SiO2 and K2O in P3. The An% of 84.4 of plagioclase coupled with CaO enrichment in P4 is suggestive of some Main Zone influence and can be interpreted as resulting from partial melting and recrystallization of P3 in response to the intrusion of the Main Zone magma is suggested for the formation of the P4 unit. There exists a good correlation between the modal mineralogy and mineral chemistry as determined optically, the norm as determined by the CIPW norm and the whole-rock geochemical results as determined by multivariate statistics and conventional methods.

Objective: Executive functions govern our ability to navigate complex and novel situations in day-to-day life. There is increased interest on environmental influences that may cause changes to executive functioning. The current thesis involves two studies examining the derivation and performance of an executive behaviour screener from the Behavioral Assessment System for Children (BASC-2-PRS; Reynolds & Kamphaus, 2004) on two different adolescent samples using a previously derived four-factor model of executive functioning (Garcia-Barrera et al., 2011, 2013). Participants and Methods: Study 1. BASC-2 PRS standardization data consisting of a demographically matched American sample of 2722 12-21 year olds was obtained. The screener was derived using 25 items assigned a priori to each executive factor. Confirmatory factor analysis (CFA), invariance testing, and multiple indicators multiple causes (MIMIC) models were used to evaluate the screener. Study 2. The screener was applied to a previously collected sample of 479 elite adolescent hockey players from Canada with or without a history of concussion, followed through a single season of play. CFA, invariance testing, and MIMIC models were used to evaluate the screener and the hockey sample was compared to the standardization sample. Results: Study 1. Acceptable-to-good reliability was obtained for all factors (α = .75-.89). The four-factor model was the best fit to the data (CFI = .990, TLI = .989, RMSEA = .037). Configural, metric, and scalar but not latent mean invariance was shown for sex. Age-related uniform differential item functioning (DIF) and SES-related uniform and non-uniform DIF were shown. Standardized norms for use in clinical settings were created. Study 2. Acceptable-to-good reliability was shown for 3 factors (α = .72-.85). Emotional Control showed poor reliability (α = .58). The four-factor model was the best fit to the data (CFI = .991, TLI = .990, RMSEA = .026). Configural, metric, and scalar but not latent mean invariance was shown between the two samples. Uniform and non-uniform DIF were not observed for those with an increasing number of past concussions. Conclusions: Findings support the four-factor model measured through the screener in adolescence. Females and hockey players demonstrate fewer executive behaviour problems overall. Sex, age, and SES may influence the interpretation of factor scores. Continued exploration and development of the screener is suggested. / Graduate / 2018-09-27

This thesis deals with the issue of increasing competitiveness in the context of sustainable growth in the European Union and the Slovak Republic. The method used in the thesis is a multivariate statistical method called factor analysis. This method enabled to narrow dimension of the input data with the least possible loss of information and consequently we obtained new variables called factors. According to the obtained factors the competitiveness of Slovak regions at NUTS II level was evaluated. Based on these results, it is possible to identify the most competitive region of the Slovak Republic which supports its growth in a sustainable way.

The aim of the thesis is to make segmentation of leisure activities market, to uncover important customer segments and describe the differences in their behavior and feature. Is used the knowledge of social sciences, particularly economics and sociology, with the help of which is described relationship of lifestyle and consumer behavior. The data come from research focused on consumer and media behavior and its relation to population lifestyle. Data were subjected to factor and cluster analysis.

Orientador: Roy Edward Bruns / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-18T15:22:35Z (GMT). No. of bitstreams: 1 Araujo_JorgePauloDantasde_M.pdf: 2024692 bytes, checksum: d5669168a2ce24885a57c2fa7cf830b8 (MD5) Previous issue date: 2011 / Resumo: O processo de desenvolvimento de motores Diesel vem sendo cada vez mais estudado e aprimorado dentro da Indústria. A busca por ferramentas que possam reduzir o tempo de desenvolvimento e também otimizar o trabalho para atingir requisitos de desempenho, redução de consumo de combustível e limites de emissões cada vez mais restritivos é muito importante. Por esse motivo, o presente trabalho pretende contribuir com informações que podem conduzir ao conhecimento necessário para aplicação de planejamento multivariado, no processo de desenvolvimento de um motor Diesel, buscando uma diminuição no tempo para realizar esta atividade. Em uma primeira fase do trabalho, foram identificados quais os componentes (fatores) que deveriam ser estudados e também as variáveis de resposta, que no caso são consumo de óleo lubrificante e pressão de recirculação dos gases de combustão (pressão de carter). Após a definição dos componentes, foram selecionados quais os níveis dos fatores a serem estudados (no caso, mudanças geométricas dos componentes). Em seguida foi aplicada a metodologia de planejamento multivariado de experimentos (fatorial completo) para identificar qual o melhor compromisso entre as configurações estudadas visando os melhores resultados das variáveis de resposta. Ao final desta fase foi possível identificar a melhor configuração entre os componentes estudados e também um ganho substancial no tempo necessário para executar esta atividade. Já em uma segunda fase do trabalho, foi realizado um estudo verificando a influência das tolerâncias de especificação de projeto de alguns componentes considerados críticos para as mesmas respostas estudadas na fase 01 (consumo de óleo e pressão de carter). Através de um estudo fatorial fracionado foi possível identificar quais são as especificações críticas a serem controladas no processo produtivo para manter os valores de consumo de óleo e pressão de carter dentro dos padrões especificados para o motor em questão / Abstract: The Diesel engine development process has been increasingly studied and improved by industry. The search for tools that can reduce development time and also optimize the work to achieve performance requirements, fuel consumption targets and restrictive emission limits is very important. For this reason, this work aims to contribute with information that may lead to knowledge necessary for the application of multivariate planning in the development process of a Diesel engine, seeking a reduction in time to perform this activity. In the first phase of this work components (factors) that should be studied and also the response variables, which are lubricating oil consumption and pressure of combustion gas recirculation (carter pressure) have been identified. After the component definitions were made the factor levels were selected for study (geometrical changes in the components). Then multivariate statistical designs were applied (full factorial) to identify the best compromise among the levels studied in order to obtain the best results for the response variables. At the end of this phase it was possible to identify the best configurations for the components studied, which also resulted in a substantial gain in the time necessary to perform this activity. In a second phase of this work, a tolerance study was carried out on the influences of the geometrical design specifications of some components considered critical for the same responses studied in phase 1 (oil consumption and carter pressure). Through a fractional factorial study it was possible to identify the critical specifications to be controlled in the productive process to maintain the values of oil consumption and carter pressure within the defaults specified for the engine in question / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Automobilistica

Approximately 80% of reproductive age women experience physical or emotional symptoms prior to onset of menses. Of these women, approximately 20% experience symptoms severe enough to interfere with social functioning and life activities and meet criteria for premenstrual syndrome (PMS). More than 100 different symptoms are associated with PMS, the most common of which include breast tenderness, headache, anger, and depression. Symptom groupings tend to be stable within an individual but can vary distinctly between women. Potential differences in the etiology of symptoms suggest that PMS should not be considered a single condition in research or clinical studies, but rather may represent distinct entities that group by symptom patterns. The primary goal of this study was to identify symptom patterns using factor and cluster analysis. Analysis included: 1) a cohort of healthy women aged 18-30 (n =414); and 2) the subgroup of women meeting established criteria for PMS (n=80). All participants provided information on the occurrence and severity of 26 menstrual symptoms by validated questionnaire. Four distinct symptom patterns emerged: Emotional, Psychological, Physical, and Consumption. Cronbach’s alpha levels demonstrating reliability were high in both the total population (0.71 – 0.90) and in the PMS subset (0.69-0.80). Additionally, cluster analysis identified 4 clusters in both the total population and PMS subset. These symptom patterns were consistent with those identified in prior studies in diverse populations. These observations suggest that distinct subtypes of PMS may exist, and should be considered when recommending treatments and evaluating risk factors.

>Magister Scientiae - MSc / The thesis aims to determine the depositional environments, rock types and petrophysical characteristics of the reservoirs in Wells E-S3, E-S5 and F-AH4 of Area X in the Bredasdorp Basin, offshore South Africa. The three wells were studied using methods including core description, petrophysical analysis, seismic facies and multivariate statistics in order to evaluate their reservoir potential. The thesis includes digital wireline log signatures, 2D seismic data, well data and core analysis from selected depths. Based on core description, five lithofacies were identified as claystone (HM1), fine to coarse grained sandstone (HM2), very fine to medium grained sandstone (HM3), fine to medium grained sandstone (HM4) and conglomerate (HM5). Deltaic and shallow marine depositional environments were also interpreted from the core description based on the sedimentary structures and ichnofossils. The results obtained from the petrophysical analysis indicate that the sandstone reservoirs show a relatively fair to good porosity (range 13-20 %), water saturation (range 17-45 %) and a predicted permeability (range 4- 108 mD) for Wells E-S3, E-S5 andF-AH4. The seismic facies model of the study area shows five seismic facies described as parallel, variable amplitude variable continuity, semi-continuous high amplitude, divergent variable amplitude and chaotic seismic facies as well as a probable shallow marine, deltaic and submarine fan depositional system. Linking lithofacies to seismic facies maps helped to understand and predict the distribution and quality of reservoir packages in the studied wells. Multivariate statistical methods of factor, discriminant and cluster analysis were used. For Wells E-S3, E-S5 and F-AH4, two factors were derived from the wireline log data reflecting oil and non- oil bearing depths. Cluster analysis delineated oil and non-oil bearing groups with similar wireline properties. This thesis demonstrates that the approach taken is useful because petrophysical analysis, seismic facies and multivariate statistics has provided useful information on reservoir quality such as net to gross, depths of hydrocarbon saturation and depositional environment.

This study aimed to explore the ability to capture the theoretical constructs of Adlerian crucial Cs (capable, connect, count, and courage) through creation of a self-report instrument for children. After following a four-phase process to develop the Crucial Cs Self Report (CCSR), including use of an expert panel, field reviews, preliminary testing, and final administration, the researcher utilized a series of exploratory factor analyses to explore the internal factor structure and relationships between items and resulting factors. The final EFA sample consisted of 112 children between the ages of 8 and 12 years recruited from various settings including three elementary schools, two mental health counseling clinics, and one private practice mental health agency. Exploratory factor analysis revealed a three-factor structure with 14 items. Refined model identified three factors later named count/significance, connect/belonging, and capable/striving. This initial exploration into the constructs of the Crucial Cs provides increased understanding of the widely used concepts. Further exploration and validation of the CCSR can help support parents and teachers in their efforts to foster healthy development of children as well as allow professionals and researchers to conceptualize progress and measure effectiveness of counseling intervention more accurately.