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Differential item functioning (DIF) occurs when individuals from different groups who have equal levels of a latent trait fail to earn commensurate scores on a testing instrument. Type I error occurs when DIF-detection methods result in unbiased items being excluded from the test while a Type II error occurs when biased items remain on the test after DIF-detection methods have been employed. Both errors create potential issues of injustice amongst examinees and can result in costly and protracted legal action. The purpose of this research was to evaluate two methods for detecting DIF: logistic regression (LR) and Mantel-Haenszel (MH). To accomplish this, meta-analysis was employed to summarize Monte Carlo quantitative studies that used these methods in published and unpublished literature. The criteria employed for comparing these two methods were Type I error rates, the Type I error proportion, which was also the Type I error effect size measure, deviation scores, and power rates. Monte Carlo simulation studies meeting inclusion criteria, with typically 15 Type I error effect sizes per study, were compared to assess how the LR and MH statistical methods function to detect DIF. Studied variables included DIF magnitude, nature of DIF (uniform or non-uniform), number of DIF items, and test length. I found that MH was better at Type I error control while LR was better at controlling Type II error. This study also provides a valuable summary of existing DIF methods and a summary of the types of variables that have been manipulated in DIF simulation studies with LR and MH. Consequently, this meta-analysis can serve as a resource for practitioners to help them choose between LR and MH for DIF detection with regard to Type I and Type II error control, and can provide insight for parameter selection in the design of future Monte Carlo DIF studies.

Cyclura ricordii is an endemic iguana from Hispaniola and is listed as Critically Endangered on the IUCN. The main threats are predation by introduced mammals, habitat destruction and hunting. The present study focused on two nesting areas in Pedernales in the Dominican Republic. The hypothesis tested is that natal philopatry influences dispersal and nest site selection. Monitoring and sampling took place during 2012-2013. Polymorphic markers were used to evaluate whether natal philopatry limits dispersal at multiple spatial scales. Ripley’s K, revealed that nests were significantly clustered. Hierarchical AMOVA revealed that nest site aggregations did not explain a significant portion of genetic variation. However, Mantel’s tests revealed significant positive correlations between genetic and geographic distance. These results indicate that natal philopatry limits dispersal at a course spatial scale, but does not influence nest site selection at a fine spatial scale.

Submitted by (ana.araujo@ufrpe.br) on 2016-05-20T12:26:11Z No. of bitstreams: 1 Ana Clara Paixao Campos.pdf: 1515481 bytes, checksum: 29c30eb35f6e7da1f6e63d0971def668 (MD5) / Made available in DSpace on 2016-05-20T12:26:11Z (GMT). No. of bitstreams: 1 Ana Clara Paixao Campos.pdf: 1515481 bytes, checksum: 29c30eb35f6e7da1f6e63d0971def668 (MD5) Previous issue date: 2013-02-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Knowing the spatial pattern of patients with genetic disease with physical disabilities in the treatment of Pernambuco AACD is of great importance because it makes it possible to guide the basic care assistance to these individuals and provide solid basis for planning public health policies. However, there are few references in the literature using the tools of spatial analysis in the context of disability. This dissertation was structured in the form of two papers. In the first article the global Moran's I index was used to characterize the spatial pattern of the rate of patients with genetic disease with physical disabilities in the AACD treatment of Pernambuco and the results were compared with those obtained with the randomization test. In both approaches we found the existence of spatial pattern for the rate of patients with genetic disease with physical disabilities in the treatment of Pernambuco AACD when we took into account the rates of four municipalities closest to each location. In the second article we evaluated the performance of the global Moran's I index and the Mantel test with Spearman correlation, both using randomization to assess the statistical significance, regarding the ability to detect spatial pattern for the rate of patients with diseases genetic with physical disabilities in the AACD treatment of Pernambuco. The results showed that the global Moran's I index proved to be a more satisfactory method for detecting the spatial pattern, since it uses the information in its calculations of the neighborhood, and provide greater control of the rejection rates of the null hypothesis under study. / Conhecer o padrão espacial dos portadores de doença genética com deficiência física em tratamento na AACD de Pernambuco é de grande importância, pois torna possível orientar a assistência aos cuidados básicos desses indivíduos e fornecer base sólida para o planejamento de políticas públicas de saúde. Entretanto, existem poucas referências na literatura utilizando o instrumental da análise espacial no contexto da deficiência física. A presente dissertação foi estruturada na forma de dois artigos científicos. No primeiro artigo o Índice I global de Moran foi utilizado para caracterizar o padrão espacial da taxa de pacientes portadores de doença genética com deficiência física em tratamento na AACD de Pernambuco e os resultados encontrados foram comparados com os obtidos através do teste de aleatorização. Em ambas as metodologias constatou-se a existência de padrão espacial agregado para a taxa de pacientes portadores de doença genética com deficiência física em tratamento na AACD de Pernambuco quando se levou em consideração as taxas dos 4 municípios mais próximos de cada localidade. No segundo artigo foi avaliado o desempenho do índice I global de Moran e do teste de Mantel com correlação de Spearman, ambos utilizando aleatorização para avaliar a significância da estatística, no que tange a capacidade de detectar padrão espacial para a taxa de pacientes portadores de doenças genéticas com deficiência física em tratamento na AACD de Pernambuco. Os resultados indicaram que o índice I global de Moran mostrou-se uma metodologia mais satisfatória para detectar do padrão espacial, uma vez que utiliza em seus cálculos as informações da vizinhança, além de proporcionar maior controle das taxas de rejeição da hipótese nula em estudo.

Les distributions d'espèces observées dans un environnement hétérogène résultent de plusieurs processus déterministes et stochastiques agissant comme des filtres pour contraindre la coexistence des espèces. L’action successive de ces processus a pour conséquence directe de structurer spatialement la composition des communautés et la variation de ces compositions (i.e., diversité bêta). Un des objectifs majeurs de l'écologie des communautés et métacommunautés consiste à identifier et quantifier les effets respectifs de ces différents processus sur la diversité bêta des communautés afin de mieux comprendre et prédire la distribution de la biodiversité. L'expérimentation étant difficilement possible, les processus responsables de la variation spatiale de la composition des communautés sont généralement inférés à partir des structures spatiales des distributions d’espèces observées dans la nature. La thèse s’inscrit dans ce contexte et vise à améliorer les outils de statistique multivariée permettant d’identifier et quantifier l'effet des processus écologiques structurant les communautés et métacommunautés. En particulier, il est proposé d’intégrer les échelles écologiques et les modèles nuls contraints pour étudier l’effet de l’environnement. La décomposition des relations trait-environnement dans les échelles spatiales et phylogénétiques permet une étude plus approfondie du filtrage environnemental en associant son échelle spatiale d’action au signal phylogénétique des traits sélectionnés pour capturer l’histoire évolutive associée au filtrage environnemental. L’interprétation en terme de processus évolutifs est néanmoins limitée et mériterait l’intégration de modèles nuls phylogénétiquement contraints pour une analyse plus fine. Dans la continuité, des modèles nuls spatialement contrains ont été développés et intégrés à deux analyses multivariées très largement utilisées en écologie des communautés (i.e., partitionnement de variation et test de Mantel) pour estimer et tester l’effet de l’environnement sur les assemblages d’espèces. Ces deux analyses présentaient une surestimation de leur statistique mesurée ainsi qu’un taux anormal de faux positifs lorsque les distributions d’espèces (via processus de dispersion limitée) et l’environnement étaient indépendamment spatialement structurés. L’intégration de modèles nuls spatialement contraints a permis d’ajuster à la fois les estimations et les tests de ces deux analyses illustrant ainsi le besoin d’utiliser des modèles nuls écologiquement contraints pour une identification et quantification correctes des processus écologiques / Species distributions observed in an heterogeneous environment result from multiple deterministic and stochastic processes acting as filters to constrain species co-existence. As a direct consequence, the successive actions of these processes spatially structure communities composition and the variation of these compositions (i.e., beta-diversity). One of the major objective in community and metacommunity ecology is to identify and quantify the respective effects of these different processes on communities beta-diversity to better understand and predict the distribution of biodiversity. Experiments being hardly possible, processes responsible for the spatial variation of communities composition are generally inferred from spatial patterns of species distributions observed in nature. In this context, the thesis aims at improving multivariate statistical tools conducted to identify and quantify the effects of ecological processes shaping communities and metacommunities. In particular, this thesis proposes to integrate ecological scales and constrained null models to study the effect of environment.Decomposing trait-environment relationships through spatial and phylogenetic scales allows to further study environmental filtering. The association of spatial scales involved in environmental filtering with the phylogenetic signals of traits allowed to capture the evolutive history related to environmental filtering. The interpretation in terms of evolutive processes is however limited and phylogenetically-constrained null models should be considered to improve the analysis. Following on from this work, spatially-constrained null models were developed and integrated into two multivariate analyses widely used in community ecology (i.e., variation partitioning and Mantel tests) to estimate and test the effect of environmental filtering on species assemblages. Both approaches presented overestimation of their computed statistic as well as high rates of false positive when species distributions (via limited dispersal) and environmental conditions were independently spatially structured. Integrating spatially-constrained null models allowed to adjust both their tests and the values of their statistic, as such demonstrating the need of using ecologically-constrained null models to correctly identify and quantify ecological processes.For future works, the thesis suggests that adopting a scaling approach to study ecological processes in addition to mechanistic null models could offer the possibility to distinguish processes from one another

In der vorliegenden Arbeit werden anhand der Edelgaszusammensetzung von Kimberliten und Lamproiten sowie ihrer gesteinsbildenden Minerale die Wechselwirkungen dieser Gesteine mit Fluiden diskutiert. Die untersuchten Proben stammen vom östlichen Baltischen Schild, vom Kola-Kraton (Poria Guba und Kandalaksha) und vom karelischen Kraton (Kostamuksha). Edelgasanalysen nach thermischer oder mechanischer Gasextraktion von 23 Gesamtgesteinsproben und 15 Mineralseparaten ergeben folgendes Bild: Helium- und Neon-Isotopendaten der Fluideinschlüsse von Lamproiten aus Kostamuksha lassen auf den Einfluss einer fluiden Phase krustaler Herkunft schliessen. Diese Wechselwirkungen fanden wahrscheinlich schon während des Magmenaufstiegs statt, denn spätere Einflüsse krustaler Fluide auf die Lamproite und ihr Nebengestein (Quarzit) sind gering, wie anhand der C/³⁶Ar-Zusammensetzung gezeigt wird. Auch sind die mit verschiedenen Datierungsmethoden (Rb-Sr, Sm-Nd, K-Ar) an Mineralseparaten und teilweise an Gesamtgestein ermittelten Alter konsistent und machen eine metamorphe Überprägung unwahrscheinlich. Aufgrund der Verteilung der primordialen Edelgasisotope zwischen Fluideinschlüssen und Gesteinsmatrix ist ein langsamer Magmenaufstieg anzunehmen, was die Möglichkeit der Kontamination mit einem krustalen Fluid während des Magmenaufstiegs erhöht.<br /> <br>Die Gasextraktion aus Mineralseparaten erfolgte thermisch, wodurch eine Freisetzung der Gase ausschließlich aus Fluideinschlüssen nicht möglich ist. Hierbei zeigen Amphibol und Klinopyroxen, separiert aus Kostamuksha-Lamproiten, in ihrer Neon-Isotopenzusammensetzung im Vergleich zur krustalen Zusammensetzung (Kennedy et al., 1990) ein leicht erhöhtes Verhältnis von ²⁰Ne/²²Ne, was ein Hinweis auf Mantel-Neon sein könnte. Kalifeldspäte, Quarz und Karbonate enthalten dagegen nur Neon krustaler Zusammensetzung. Phlogopite haben sehr kleine Verhältnisse von ²⁰Ne/²²Ne und ²¹Ne/²²Ne, zurückzuführen auf in-situ-Produktion von ²²Ne in Folge von U- und Th-Zerfallsprozessen.<br><br /> Wie unterschiedliche thermische Entgasungsmuster für ⁴⁰Ar und ³⁶Ar zeigen, ist ³⁶Ar in Fluideinschlüssen konzentriert. Das ⁴⁰Ar/³⁶Ar-Isotopenverhältnis der Fluideinschlüsse von Lamproiten aus Kostamuksha ist antikorreliert mit der durch thermische Extraktion bestimmten Gesamtmenge an ³⁶Ar. Argon aus Fluideinschlüssen setzt sich daher aus zwei Komponenten zusammen: Einer Komponente mit atmosphärischer Argon-Isotopenzusammensetzung und einer krustalen Komponente mit einem Isotopenverhältnis ⁴⁰Ar/³⁶Ar > 6000. Diffusion von radiogenem ⁴⁰Ar aus der Kristallmatrix in die Fluideinschlüsse spielt keine wesentliche Rolle.<br /> <br>Kimberlite aus Poria Guba und Kandalaksha zeigen anhand der Helium- und z. T. auch der Neon-Isotopenzusammensetzung eine Mantelkomponente in den Fluideinschlüssen an. Bei einem angenommenen ²⁰Ne/²²Ne-Isotopenverhältnis von 12,5 in der Mantelquelle ergibt sich ein ²¹Ne/²²Ne-Isotopenverhältnis von 0,073 ± 0,011 sowie ein ³He/⁴He-Isotopenverhältnis, welches im Vergleich zum subkontinentalem Mantel (Dunai und Baur, 1995) stärker radiogen geprägt ist. Solche Isotopensignaturen sind mit höheren Konzentrationen an Uran und Thorium in der Mantelquelle der Kimberlite zu erklären.<br /> <br>Rb-Sr- und Sm-Nd-Altersbestimmungen erfolgten von russischer Seite (Belyatskii et al., 1997; Nikitina et al., 1999) und ergeben ein Alter von 1,23 Ga für den Lamproitvulkanismus in Kostamuksha. Eigene K-Ar-Datierungen an Phlogopiten und Kalifeldspäten stimmen mit einem Alter von 1193 ± 20 Ma fast mit den Rb-Sr- und Sm-Nd-Altern überein. Die K-Ar-Datierung an einem Phlogopit aus Poria Guba, separiert aus dem Kimberlit PGK 12a, ergibt ein Alter von 396 Ma, ebenfalls in guter Übereinstimmung mit Rb-Sr-und Sm-Nd-Altern (ca. 400 Ma, Lokhov, pers. Mitteilung). K-Ar-Altersbestimmungen an Gesamtgestein aus Poria Guba erbrachten kein schlüssiges Alter. Die Rb-Sr- und Sm-Nd-Alter des Lamproitmagmatismus in Poria Guba betragen 1,72 Ga (Nikitina et al., 1999).<br /> <br>Vergleiche von gemessenen mit berechneten Edelgaskonzentrationen aus in-situ-Produktion zeigen weiterhin, dass in Abhängigkeit vom Alter der Probe Diffusionsprozesse stattgefunden haben, die zu unterschiedlichen und z. T. erheblichen Verlusten an Helium und Neon führten. Diffusionsverluste an Argon sind dagegen kaum signifikant. Unterschiedliche Diffusionsverluste in Abhängigkeit von Alter und betrachtetem Edelgas zeigen auch die primordialen Edelgase. / In the present thesis, interactions of kimberlites and lamproites as well as their constituent minerals with fluids are discussed based on noble gas compositions. The samples originate from the eastern Baltic Shield, more specifically from the Kola craton (Poria Guba and Kandalaksha) and the Karelia craton (Kostamuksha). Gas was extracted by stepwise heating and crushing from 23 whole rock samples and 15 mineral separates. These two techniques allow differential extraction of gas from fluid inclusions (crushing technique) and from the bulk sample (stepwise heating). The noble gas analyses provide the following information:</P> <P>Helium and neon isotopic compositions of fluid inclusions in lamproites reveal the presence of a crustal fluid phase. Fluid interaction probably ocurred already during the process of magma ascent. Interaction after lamproite emplacement seems unlikely. The lamproites and their host rock differ in the degree of fluid-rock interaction, as demonstrated by the C/³⁶Ar composition. In addition, various dating methods (Rb-Sr, Sm-Nd, K-Ar) yield almost the same age within analytical error. Thus, a metamorphic overprint can be excluded. The distribution of primordial noble gases between fluid inclusions and crystal lattice suggests a relatively slow magma ascent, making an interaction of the lamproitic magma with crustal fluids even more likely. Since noble gases from mineral separates were extracted only by the stepwise heating method, gases stored in fluid inclusions could not be released separately.</P> <P>Amphibole and clinopyroxene separates yielded a higher ²⁰Ne/²²Ne ratio in comparison to crustal composition (Kennedy et al., 1990). This presumably is an indication of a mantle derived fluid phase. On the other hand, neon isotopic composition of K-feldspar, quartz and carbonate separates are indistinguishable from the crustal composition. In comparison to other mineral separates, phlogopite yields very low ratios of ²⁰Ne/²²Ne and ²¹Ne/²²Ne due to in situ production of ²²Ne, which is a result of nuclear reactions.</P> <P>The distinct thermal gas release patterns of ⁴⁰Ar and ³⁶Ar indicates that ³⁶Ar is concentrated in fluid inclusions. The ⁴⁰Ar/³⁶Ar isotopic ratio in fluid inclusions shows a negative correlation with the total amount of ³⁶Ar released by thermal extraction. Therefore, argon from fluid inclusions is a simple 2-component mixture of air and a crustal component with an ⁴⁰Ar/³⁶Ar ratio > 6000. It can be shown that diffusion of ⁴⁰Ar from the matrix into fluid inclusions is negligible.</P> <P>In contrast to lamproites, whole rock kimberlite samples from Poria Guba and Kandalaksha show clear evidence in helium and, to a certain extentalso in neon isotope ratios, of interaction with a mantle derived fluid phase. Assuming a ²⁰Ne/²²Ne ratio of 12.5 for the mantle endmember, a ²¹Ne/²² Ne ratio of 0.073 ± 0.011 can be calculated. Likewise, the resulting ³He/⁴He ratio is more strongly influenced by radiogenic helium in comparison to the mean subcontinental mantle (Dunai und Baur, 1995). Such behaviour reflects higher concentrations of uranium and thorium in the magma source of kimberlites than the subcontinental mantle.</P> <P>Rb-Sr and Sm-Nd age determinations (Belyatskii et al., 1997; Nikitina et al., 1999) yield 1.23 Ga for the lamproite magmatism in Kostamuksha. K-Ar dating of phlogopite and K-feldspar provides similar ages (1.19 Ga). K-Ar dating of a single phlogopite separate from the Kimberlite sample PGK12a from Poria Guba, yields an age of 396 Ma which corresponds well with Rb-Sr and Sm-Nd ages.</P> <P>Depending on sample age, distinct and partly extensive diffusive loss of helium and neon has occurred, as shown by comparison of measured and calculated concentrations of in situ produced isotopes. Diffusion loss is negligible for argon. This is also strongly supported by primordial noble gas composition.

Die P- und S-Wellen-Geschwindigkeitsstruktur der D&rdquo; Schicht unter dem südwestlichen Pazifik wurde mittels kurzperiodischer Daten von 12 Tiefbeben in der Tonga-Fiji-Region untersucht, die vom J-Array und Hi-net-Array in Japan registriert wurden. Es wurde für Punktstreuer und ebene Schichten migriert, um schwache Signale zu extrahieren, die an relativ kleinräumigen Heterogenitäten des unteren Mantels entstehen. Um eine höhere Auflösung zu erzielen, wurde die Double Array-Methode (DAM) verwendet, die Empfängerarray und Quellarray gleichzeitig nutzt. Hierbei ist auch das Phase-Weighted Stack-Verfahren angewendet worden, um inkohärentes Rauschen zu reduzieren und somit schwache kohärente Signale aus dem unteren Mantel aufzulösen. Das Ergebnis der Ebenen-Schichten-Methode (RWB) zeigt, dass sich in der D&rdquo;-Schicht negative Geschwindigkeitsdiskontinuitäten mit P-Wellen Geschwindigkeitskontrasten von höchstens &ndash;1 % in den Tiefen von 2520 km und 2650 km befinden. Zusätzlich befindet sich eine positive Geschwindigkeitsdiskontinuitäten in der Tiefe von 2800 km. Bei den S Wellen treten Geschwindigkeitsdiskontinuitäten in einer Tiefe von etwa 2550 km und 2850 km auf. Die scheinbare Verschiebung (50 km) der S-Wellen-Geschwindigkeitsdiskontinuität in der Tiefe von 2850 km deutet darauf hin, daß die S-Wellen-Geschwindigkeitsreduktion im unteren Mantel 2-3 mal stärker ist als die P- Wellen-Geschwindigkeitsreduktion. Ein zweidimensionaler Querschnitt, der mittels der RWB Methode und der Aufspaltung des Gesamtempfängerarrays in Subarrays gewonnen wurde, deutet darauf hin, dass die beobachteten Diskontinuitäten als intermittierende laterale Heterogenitäten mit einer Wellenlänge von einigen hundert km charakterisiert werden können. Die Kern-Mantel-Grenze (KMG) weist möglicherweise Undulationen mit einer Amplitude von 10 km auf. Die Migration weist nur schwache Hinweise für räumliche Streukörper auf. Die in der Migration abgebildeten heterogenen Regionen korrespondieren mit den mittels der RWB Methode gefundenen seismischen Diskontinuitäten. Bei den gefundenen Heterogenitäten könnte es sich um einen Teil eines aufsteigenden heißen Stroms unter dem südwestlichen Pazifik handeln. / The P- and S-wave velocity structure of the D&rdquo; layer beneath the southwestern Pacific was investigated by using short-period data from 12 deep events in the Tonga-Fiji region recorded by the J-Array and the Hi-net in Japan. A migration method and reflected wave beamforming (RWB) were used in order to extract weak signals originating from small-scale heterogeneities in the lowermost mantle. In order to acquire high resolution, a double array method (DAM) which integrates source array beamforming with receiver array beamforming was applied to the data. A phase-weighted stacking technique, which reduces incoherent noise by employing complex trace analysis, was also applied to the data, amplifying the weak coherent signals from the lowermost mantle. This combination greatly enhances small phases common to the source and receiver beams. The results of the RWB method indicate that seismic energy is reflected at discontinuities near 2520 km and 2650 km, which have a negative P-wave velocity contrast of 1 % at the most. In addition, there is a positive seismic discontinuity at a depth of 2800 km. In the case of the S-wave, reflected energy is produced almost at the same depth (2550 km depth). The different depth (50 km) between the P-wave velocity discontinuity at the depth of 2800 and a further S-wave velocity discontinuity at the depth of 2850 km may indicate that the S-wave velocity reduction in the lowermost mantle is about 2-3 times stronger that that of P wave. A look at a 2D cross section, constructed with the RWB method, suggests that the observed discontinuities can be characterized as intermittent lateral heterogeneities whose lateral extent is a few hundred km, and that the CMB might have undulations on a scale of less than 10 km in amplitude. The migration shows only weak evidence for the existence of scattering objects. Heterogeneous regions in the migration belong to the detected seismic discontinuities. These anomalous structures may represent a part of hot plume generated beneath the southwestern Pacific in the lowermost mantle.

This dissertation served two purposes. The first was to develop a method of detecting differential item functioning (DIF) within tests containing both dichotomously and polytomously scored items. The second was related to gender and aimed a) to investigate if those items that were functioning differently for girls and boys showed any characteristic properties and, if so, b) determine if these properties could be used to predict which items would be flagged for D1F. The method development was based on the Mantel-Haenszel (MH) method used for dichotmously scored items. By dichotomizing the polytomously scored items both types of item could be compared on the same statistical level as either solved or non-solved items. It was not possible to compare the internal score structures for the two gender groups, only overall score differences were detected. By modelling the empirical item characteristic curves it was possible to develop a MH method for identifying nonuniform DIF. Both internal and external ability criteria were used. Total test score with no purification was used as the internal criterion. Purification was not done for validity reasons, no items were judged as biased. Teacher set marks were used as external criteria. The marking scale had to be transformed for either boys or girls since a comparison of scores for boys and girls with the same marks showed that boys always got higher mean scores. The results of the two MH analyses based on internal and external criterion were compared with results from P-SIBTEST. All three methods corresponded well although P-SIBTEST flagged considerably more items in favour of the reference group (boys) which exhibited a higher overall ability. All 200 items included in the last 15 annual national tests in physics were analysed for DIF and classified by ten criteria The most significant result was that items in electricity were, to a significantly higher degree, flagged as DIF in favour of girls whilst items in mechanics were flagged in favour of boys. Items in other content areas showed no significant pattern. Multiple-Choice items were flagged in favour of boys. Regardless of the degree of significance by which items from different content areas were flagged on a group level it was not possible to predict which single item would be flagged for DIF. The most probable prediction was always that an item was neutral. Some possible interpretations of DIF as an effect of multidimen-sionality were discussed as were some hypotheses about the reasons why boys did better in mechanics and girls in electricity. / digitalisering@umu

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-20T21:22:09Z No. of bitstreams: 1 RobivalAlvesRibeiro_TESE.pdf: 2206825 bytes, checksum: 2cb9e24716fd72830d590b545945791d (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-22T20:33:51Z (GMT) No. of bitstreams: 1 RobivalAlvesRibeiro_TESE.pdf: 2206825 bytes, checksum: 2cb9e24716fd72830d590b545945791d (MD5) / Made available in DSpace on 2016-01-22T20:33:51Z (GMT). No. of bitstreams: 1 RobivalAlvesRibeiro_TESE.pdf: 2206825 bytes, checksum: 2cb9e24716fd72830d590b545945791d (MD5) Previous issue date: 2014-12-17 / Esta pesquisa tem como objetivo verificar se ? poss?vel construir padr?es espaciais em reservat?rios de petr?leo, usando expoentes de DFA (Detrended Fluctuation Analysis) dos diferentes perfis geol?gicos como: s?nico, densidade, porosidade, resistividade e raios gama. Fizeram parte da amostra 54 po?os de petr?leo do campo de Namorado, localizados na bacia de Campos, no estado do Rio de Janeiro, Brasil. Com o intuito de verificar a correla??o linear, constru?ram-se matrizes de dist?ncias entre os po?os e matrizes de diferen?as entre os DFA dos po?os, comparadas duas a duas e utilizado como m?todo estat?stico o teste de Mantel. A hip?tese nula consiste em afirmar que n?o existe correla??o linear entre as estruturas espaciais formadas pelas matrizes de dist?ncias euclidianas e das diferen?as dos expoentes de DFA dos perfis geol?gicos. Os perfis s?nicos (p=0,18) e da densidade (p=0,26) foram os que revelaram uma tend?ncia ? correla??o ou correla??o fraca. Estudo complementar, utilizando o contour plot, mostra os padr?es s?nicos e da densidade compat?veis com presen?a de correla??o espacial, corroborando os revelados pelo teste de Mantel / This research aims to set whether is possible to build spatial patterns over oil fields using DFA (Detrended Fluctuation Analysis) of the following well logs: sonic, density, porosity, resistivity and gamma ray. It was employed in the analysis a set of 54 well logs from the oil field of Campos dos Namorados, RJ, Brazil. To check for spatial correlation, it was employed the Mantel test between the matrix of geographic distance and the matrix of the difference of DFA exponents of the well logs. The null hypothesis assumes the absence of spatial structures that means no correlation between the matrix of Euclidean distance and the matrix of DFA differences. Our analysis indicate that the sonic (p=0.18) and the density (p=0.26) were the profiles that show tendency to correlation, or weak correlation. A complementary analysis using contour plot also has suggested that the sonic and the density are the most suitable with geophysical quantities for the construction of spatial structures corroborating the results of Mantel test

abstract: The study examined how ATFIND, Mantel-Haenszel, SIBTEST, and Crossing SIBTEST function when items in the dataset are modelled to differentially advantage a lower ability focal group over a higher ability reference group. The primary purpose of the study was to examine ATFIND's usefulness as a valid subtest selection tool, but it also explored the influence of DIF items, item difficulty, and presence of multiple examinee populations with different ability distributions on both its selection of the assessment test (AT) and partitioning test (PT) lists and on all three differential item functioning (DIF) analysis procedures. The results of SIBTEST were also combined with those of Crossing SIBTEST, as might be done in practice. ATFIND was found to be a less-than-effective matching subtest selection tool with DIF items that are modelled unidimensionally. If an item was modelled with uniform DIF or if it had a referent difficulty parameter in the Medium range, it was found to be selected slightly more often for the AT List than the PT List. These trends were seen to increase as sample size increased. All three DIF analyses, and the combined SIBTEST and Crossing SIBTEST, generally were found to perform less well as DIF contaminated the matching subtest, as well as when DIF was modelled less severely or when the focal group ability was skewed. While the combined SIBTEST and Crossing SIBTEST was found to have the highest power among the DIF analyses, it also was found to have Type I error rates that were sometimes extremely high. / Dissertation/Thesis / Doctoral Dissertation Educational Psychology 2014