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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Utiliza??o de ferramenta de realidade aumentada para ajudar em tarefas psicopedag?gicas com crian?as pertencentes ao transtorno do espectro autista

Soares, Kerolayne Paiva 19 October 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-02-21T21:29:06Z No. of bitstreams: 1 KerolaynePaivaSoares_TESE.pdf: 14474619 bytes, checksum: c7fe8c3bad13343debb34f5675472ff3 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-02-22T23:29:20Z (GMT) No. of bitstreams: 1 KerolaynePaivaSoares_TESE.pdf: 14474619 bytes, checksum: c7fe8c3bad13343debb34f5675472ff3 (MD5) / Made available in DSpace on 2018-02-22T23:29:21Z (GMT). No. of bitstreams: 1 KerolaynePaivaSoares_TESE.pdf: 14474619 bytes, checksum: c7fe8c3bad13343debb34f5675472ff3 (MD5) Previous issue date: 2017-10-19 / A presente tese tem como objetivo mostrar o desenvolvimento e aplica??o de uma ferramenta em Realidade Aumentada para ajudar crian?as afetadas com Transtorno do Espectro Autista (TEA). Tal ferramenta consiste na exibi??o de cenas caricaturadas da vida real, atrav?s dos ?culos de Realidade Virtual Google Cardboard, que foram utilizadas em tarefas e testes psicopedag?gicos, realizados com essas crian?as. Analisamos os relacionamentos sobre a poss?vel melhoria nas fun??es executivas quando essas t?m seu processamento facial suavizado usando o sistema proposto e vendo o mundo real como um desenho animado. Este estudo inicial fornece evid?ncias para verificar que tais crian?as t?m um interesse particular em desenho animado a despeito de faces humanas. Os resultados alcan?ados sugerem que o ambiente proposto ajuda a aumentar o desempenho das crian?as em tarefas psicopedag?gicas e que pode ser uma ferramenta ?til para ajudar os profissionais em educa??o a proporcionar um melhor suporte a essas crian?as, principalmente no que diz respeito ao desenvolvimento de suas fun??es executivas. / The present thesis aims to show the development and application of an Augmented Reality tool to helps children affected with Autistic Spectrum Disorder (ASD).This tool consists of the display of real-life caricatured scenes, visualized through the Google Cardboard Virtual Reality glasses, which were used in tasks and psychopedagogical tests performed with these children. We analyzed the relationships about the possible increase in executive functions when they have their facial processing smoothed using the proposed system and seeing the real world as a cartoon. This initial study provides evidences to verify that such children have a particular interest in cartoon in spite of human faces. The results suggest that the proposed environment helps to increase children?s performance in psychopedagogical tasks and that it can be a useful tool to help professionals in education in their work to provide better support to these children, especially with regard to development of executive functions of them.
2

Impacts analysis for inverse integrated assessments of climate change

Füssel, Hans-Martin January 2003 (has links)
Diese Dissertation beschreibt die Entwicklung und Anwendung des Klimawirkungsmoduls des ICLIPS-Modells, eines integrierten Modells des Klimawandels ('Integrated Assessment'-Modell). Vorangestellt ist eine Diskussion des gesellschaftspolitischen Kontexts, in dem modellbasiertes 'Integrated Assessment' stattfindet, aus der wichtige Anforderungen an die Spezifikation des Klimawirkungsmoduls abgeleitet werden. <br /> <br /> Das 'Integrated Assessment' des Klimawandels umfasst eine weiten Bereich von Aktivitäten zur wissenschaftsbasierten Unterstützung klimapolitischer Entscheidungen. Hierbei wird eine Vielzahl von Ansätzen verfolgt, um politikrelevante Informationen über die erwarteten Auswirkungen des Klimawandels zu berücksichtigen. Wichtige Herausforderungen in diesem Bereich sind die große Bandbreite der relevanten räumlichen und zeitlichen Skalen, die multifaktorielle Verursachung vieler 'Klimafolgen', erhebliche wissenschaftliche Unsicherheiten sowie die Mehrdeutigkeit unvermeidlicher Werturteile. Die Entwicklung eines hierarchischen Konzeptmodells erlaubt die Strukturierung der verschiedenen Ansätze sowie die Darstellung eines mehrstufigen Entwicklungsprozesses, der sich in der Praxis und der zu Grunde liegenden Theorie von Studien zur Vulnerabilität hinsichtlich des Klimawandels wiederspiegelt. <br /> <br /> 'Integrated Assessment'-Modelle des Klimawandels sind wissenschaftliche Werkzeuge, welche eine vereinfachte Beschreibung des gekoppelten Mensch-Klima-Systems enthalten. Die wichtigsten entscheidungstheoretischen Ansätze im Bereich des modellbasierten 'Integrated Assessment' werden im Hinblick auf ihre Fähigkeit zur adäquaten Darstellung klimapolitischer Entscheidungsprobleme bewertet. Dabei stellt der 'Leitplankenansatz' eine 'inverse' Herangehensweise zur Unterstützung klimapolitischer Entscheidungen dar, bei der versucht wird, die Gesamtheit der klimapolitischen Strategien zu bestimmen, die mit einer Reihe von zuvor normativ bestimmten Mindestkriterien (den sogenannten 'Leitplanken') verträglich sind. Dieser Ansatz verbindet bis zu einem gewissen Grad die wissenschaftliche Strenge und Objektivität simulationsbasierter Ansätze mit der Fähigkeit von Optimierungsansätzen, die Gesamtheit aller Entscheidungsoptionen zu berücksichtigen. Das ICLIPS-Modell ist das erste 'Integrated Assessment'-Modell des Klimawandels, welches den Leitplankenansatz implementiert. <br /> <br /> Die Darstellung von Klimafolgen ist eine wichtige Herausforderung für 'Integrated Assessment'-Modelle des Klimawandels. Eine Betrachtung bestehender 'Integrated Assessment'-Modelle offenbart große Unterschiede in der Berücksichtigung verschiedener vom Klimawandel betroffenen Sektoren, in der Wahl des bzw. der Indikatoren zur Darstellung von Klimafolgen, in der Berücksichtigung nicht-klimatischer Entwicklungen einschließlich gezielter Anpassungsmaßnahmen an den Klimawandel, in der Behandlung von Unsicherheiten und in der Berücksichtigung von 'singulären' Ereignissen. 'Integrated Assessment'-Modelle, die auf einem Inversansatz beruhen, stellen besondere Anforderungen an die Darstellung von Klimafolgen. Einerseits muss der Detaillierungsgrad hinreichend sein, um Leitplanken für Klimafolgen sinnvoll definieren zu können; andererseits muss die Darstellung effizient genug sein, um die Gesamtheit der möglichen klimapolitischen Strategien erkunden zu können. Großräumige Singularitäten können häufig durch vereinfachte dynamische Modelle abgebildet werden. Diese Methode ist jedoch weniger geeignet für reguläre Klimafolgen, bei denen die Bestimmung relevanter Ergebnisse in der Regel die Berücksichtigung der Heterogenität von klimatischen, naturräumlichen und sozialen Faktoren auf der lokalen oder regionalen Ebene erfordert. <br /> <br /> Klimawirkungsfunktionen stellen sich als die geeignetste Darstellung regulärer Klimafolgen im ICLIPS-Modell heraus. Eine Klimawirkungsfunktion beschreibt in aggregierter Form die Reaktion eines klimasensitiven Systems, wie sie von einem geographisch expliziten Klimawirkungsmodell für eine repräsentative Teilmenge möglicher zukünftiger Entwicklungen simuliert wurde. Die in dieser Arbeit vorgestellten Klimawirkungsfunktionen nutzen die globale Mitteltemperatur sowie die atmosphärische CO2-Konzentration als Prädiktoren für global und regional aggregierte Auswirkungen des Klimawandels auf natürliche Ökosysteme, die landwirtschaftliche Produktion und die Wasserverfügbarkeit. Die Anwendung einer 'Musterskalierungstechnik' ermöglicht hierbei die Berücksichtigung der regionalen und saisonalen Muster des Klimaänderungssignals aus allgemeinen Zirkulationsmodellen, ohne die Effizienz der dynamischen Modellkomponenten zu beeinträchtigen. <br /> <br /> Bemühungen zur quantitativen Abschätzung zukünftiger Klimafolgen sehen sich bei der Wahl geeigneter Indikatoren in der Regel einem Zielkonflikt zwischen der Relevanz eines Indikators für Entscheidungsträger und der Zuverlässigkeit, mit der dieser bestimmt werden kann, gegenüber. Eine Reihe von nichtmonetären Indikatoren zur aggregierten Darstellung von Klimafolgen in Klimawirkungsfunktionen wird präsentiert, welche eine Balance zwischen diesen beiden Zielen anstreben und gleichzeitig die Beschränkungen berücksichtigen, die sich aus anderen Komponenten des ICLIPS-Modells ergeben. Klimawirkungsfunktionen werden durch verschiedene Typen von Diagrammen visualisiert, welche jeweils unterschiedliche Perspektiven auf die Ergebnismenge der Klimawirkungssimulationen erlauben.<br /> <br /> Die schiere Anzahl von Klimawirkungsfunktionen verhindert ihre umfassende Darstellung in dieser Arbeit. Ausgewählte Ergebnisse zu Veränderungen in der räumlichen Ausdehnung von Biomen, im landwirtschaftlichen Potential verschiedener Länder und in der Wasserverfügbarkeit in mehreren großen Einzugsgebieten werden diskutiert. Die Gesamtheit der Klimawirkungsfunktionen wird zugänglich gemacht durch das 'ICLIPS Impacts Tool', eine graphische Benutzeroberfläche, die einen bequemen Zugriff auf über 100.000 Klimawirkungsdiagramme ermöglicht. Die technischen Aspekte der Software sowie die zugehörige Datenbasis wird beschrieben. <br /> <br /> Die wichtigste Anwendung von Klimawirkungsfunktionen ist im 'Inversmodus', wo sie genutzt werden, um Leitplanken zur Begrenzung von Klimafolgen in gleichzeitige Randbedingungen für Variablen aus dem optimierenden ICLIPS-Klima-Weltwirtschafts-Modell zu übersetzen. Diese Übersetzung wird ermöglicht durch Algorithmen zur Bestimmung von Mengen erreichbarer Klimazustände ('reachable climate domains') sowie zur parametrisierten Approximation zulässiger Klimafenster ('admissible climate windows'), die aus Klimawirkungsfunktionen abgeleitet werden. Der umfassende Bestand an Klimawirkungsfunktionen zusammen mit diesen Algorithmen ermöglicht es dem integrierten ICLIPS-Modell, in flexibler Weise diejenigen klimapolitischen Strategien zu bestimmen, welche bestimmte in biophysikalischen Einheiten ausgedrückte Begrenzungen von Klimafolgen explizit berücksichtigen. Diese Möglichkeit bietet kein anderes intertemporal optimierendes 'Integrated Assessment'-Modell. Eine Leitplankenanalyse mit dem integrierten ICLIPS-Modell unter Anwendung ausgewählter Klimawirkungsfunktionen für Veränderungen natürlicher Ökosysteme wird beschrieben. In dieser Analyse werden so genannte 'notwendige Emissionskorridore' berechnet, die vorgegebene Beschränkungen hinsichtlich der maximal zulässigen globalen Vegetationsveränderungen und der regionalen Klimaschutzkosten berücksichtigen. Dies geschieht sowohl für eine 'Standardkombination' der drei gewählten Kriterien als auch für deren systematische Variation. <br /> <br /> Eine abschließende Diskussion aktueller Entwicklungen in der 'Integrated Assessment'-Modellierung stellt diese Arbeit mit anderen einschlägigen Bemühungen in Beziehung. / This thesis describes the development and application of the impacts module of the ICLIPS model, a global integrated assessment model of climate change. The presentation of the technical aspects of this model component is preceded by a discussion of the sociopolitical context for model-based integrated assessments, which defines important requirements for the specification of the model.<br /> <br /> Integrated assessment of climate change comprises a broad range of scientific efforts to support the decision-making about objectives and measures for climate policy, whereby many different approaches have been followed to provide policy-relevant information about climate impacts. Major challenges in this context are the large diversity of the relevant spatial and temporal scales, the multifactorial causation of many climate impacts', considerable scientific uncertainties, and the ambiguity associated with unavoidable normative evaluations. A hierarchical framework is presented for structuring climate impact assessments that reflects the evolution of their practice and of the underlying theory.<br /> <br /> Integrated assessment models of climate change (IAMs) are scientific tools that contain simplified representations of the relevant components of the coupled society-climate system. The major decision-analytical frameworks for IAMs are evaluated according to their ability to address important aspects of the pertinent social decision problem. The guardrail approach is presented as an inverse' framework for climate change decision support, which aims to identify the whole set of policy strategies that are compatible with a set of normatively specified constraints (guardrails'). This approach combines, to a certain degree, the scientific rigour and objectivity typical of predictive approaches with the ability to consider virtually all decision options that is at the core of optimization approaches. The ICLIPS model is described as the first IAM that implements the guardrail approach.<br /> <br /> The representation of climate impacts is a key concern in any IAM. A review of existing IAMs reveals large differences in the coverage of impact sectors, in the choice of the impact numeraire(s), in the consideration of non-climatic developments, including purposeful adaptation, in the handling of uncertainty, and in the inclusion of singular events. IAMs based on an inverse approach impose specific requirements to the representation of climate impacts. This representation needs to combine a level of detail and reliability that is sufficient for the specification of impact guardrails with the conciseness and efficiency that allows for an exploration of the complete domain of plausible climate protection strategies. Large-scale singular events can often be represented by dynamic reduced-form models. This approach, however, is less appropriate for regular impacts where the determination of policy-relevant results generally needs to consider the heterogeneity of climatic, environmental, and socioeconomic factors at the local or regional scale.<br /> <br /> Climate impact response functions (CIRFs) are identified as the most suitable reduced-form representation of regular climate impacts in the ICLIPS model. A CIRF depicts the aggregated response of a climate-sensitive system or sector as simulated by a spatially explicit sectoral impact model for a representative subset of plausible futures. In the CIRFs presented here, global mean temperature and atmospheric CO2 concentration are used as predictors for global and regional impacts on natural vegetation, agricultural crop production, and water availability. Application of a pattern scaling technique makes it possible to consider the regional and seasonal patterns in the climate anomalies simulated by several general circulation models while ensuring the efficiency of the dynamic model components.<br /> <br /> Efforts to provide quantitative estimates of future climate impacts generally face a trade-off between the relevance of an indicator for stakeholders and the exactness with which it can be determined. A number of non-monetary aggregated impact indicators for the CIRFs is presented, which aim to strike the balance between these two conflicting goals while taking into account additional constraints of the ICLIPS modelling framework. Various types of impact diagrams are used for the visualization of CIRFs, each of which provides a different perspective on the impact result space.<br /> <br /> The sheer number of CIRFs computed for the ICLIPS model precludes their comprehensive presentation in this thesis. Selected results referring to changes in the distribution of biomes in different biogeographical regions, in the agricultural potential of various countries, and in the water availability in selected major catchments are discussed. The full set of CIRFs is accessible via the ICLIPS Impacts Tool, a graphical user interface that provides convenient access to more than 100,000 impact diagrams developed for the ICLIPS model. The technical aspects of the software are described as well as the accompanying database of CIRFs.<br /> <br /> The most important application of CIRFs is in inverse' mode, where they are used to translate impact guardrails into simultaneous constraints for variables from the optimizing ICLIPS climate-economy model. This translation is facilitated by algorithms for the computation of reachable climate domains and for the parameterized approximation of admissible climate windows derived from CIRFs. The comprehensive set of CIRFs, together with these algorithms, enables the ICLIPS model to flexibly explore sets of climate policy strategies that explicitly comply with impact guardrails specified in biophysical units. This feature is not found in any other intertemporally optimizing IAM. A guardrail analysis with the integrated ICLIPS model is described that applies selected CIRFs for ecosystem changes. So-called necessary carbon emission corridors' are determined for a default choice of normative constraints that limit global vegetation impacts as well as regional mitigation costs, and for systematic variations of these constraints.<br /> <br /> A brief discussion of recent developments in integrated assessment modelling of climate change connects the work presented here with related efforts.
3

Particle-in-cell simulations of electron dynamics in low pressure discharges with magnetic fields

Sydorenko, Dmytro 14 June 2006
In modern low pressure plasma discharges, the electron mean free path often exceeds the device dimensions. Under such conditions the electron velocity distribution function may significantly deviate from Maxwellian, which strongly affects the discharge properties. The description of such plasmas has to be kinetic and often requires the use of numerical methods. This thesis presents the study of kinetic effects in inductively coupled plasmas and Hall thrusters carried out by means of particle-in-cell simulations. The important result and the essential part of the research is the development of particle-in-cell codes. <p>An advective electromagnetic 1d3v particle-in-cell code is developed for modelling the inductively coupled plasmas. An electrostatic direct implicit 1d3v particle-in-cell code EDIPIC is developed for plane geometry simulations of Hall thruster plasmas. The EDIPIC code includes several physical effects important for Hall thrusters: collisions with neutral atoms, turbulence, and secondary electron emission. In addition, the narrow sheath regions crucial for plasma-wall interaction are resolved in simulations. The code is parallelized to achieve fast run times. <p>Inductively coupled plasmas sustained by the external RF electromagnetic field are widely used in material processing reactors and electrodeless lighting sources. In a low pressure inductive discharge, the collisionless electron motion strongly affects the absorption of the external electromagnetic waves and, via the ponderomotive force, the density profile. The linear theory of the anomalous skin effect based on the linear electron trajectories predicts a strong decrease of the ponderomotive force for warm plasmas. Particle-in-cell simulations show that the nonlinear modification of electron trajectories by the RF magnetic field partially compensates the effects of electron thermal motion. As a result, the ponderomotive force in warm collisionless plasmas is stronger than predicted by linear kinetic theory. <p>Hall thrusters, where plasma is maintained by the DC electric field crossed with the stationary magnetic field, are efficient low-thrust devices for spacecraft propulsion. The energy exchange between the plasma and the wall in Hall thrusters is enhanced by the secondary electron emission, which strongly affects electron temperature and, subsequently, thruster operation. Particle-in-cell simulations show that the effect of secondary electron emission on electron cooling in Hall thrusters is quite different from predictions of previous fluid studies. Collisionless electron motion results in a strongly anisotropic, nonmonotonic electron velocity distribution function, which is depleted in the loss cone, subsequently reducing the electron wall losses compared to Maxwellian plasmas. Secondary electrons form two beams propagating between the walls of a thruster channel in opposite radial directions. The secondary electron beams acquire additional energy in the crossed external electric and magnetic fields. The energy increment depends on both the field magnitudes and the electron flight time between the walls. <p>A new model of secondary electron emission in a bounded plasma slab, allowing for emission due to the counter-propagating secondary electron beams, is developed. It is shown that in bounded plasmas the average energy of plasma bulk electrons is far less important for the space charge saturation of the sheath than it is in purely Maxwellian plasmas. A new regime with relaxation oscillations of the sheath has been identified in simulations. Recent experimental studies of Hall thrusters indirectly support the simulation results with respect to the electron temperature saturation and the channel width effect on the thruster discharge.
4

Particle-in-cell simulations of electron dynamics in low pressure discharges with magnetic fields

Sydorenko, Dmytro 14 June 2006 (has links)
In modern low pressure plasma discharges, the electron mean free path often exceeds the device dimensions. Under such conditions the electron velocity distribution function may significantly deviate from Maxwellian, which strongly affects the discharge properties. The description of such plasmas has to be kinetic and often requires the use of numerical methods. This thesis presents the study of kinetic effects in inductively coupled plasmas and Hall thrusters carried out by means of particle-in-cell simulations. The important result and the essential part of the research is the development of particle-in-cell codes. <p>An advective electromagnetic 1d3v particle-in-cell code is developed for modelling the inductively coupled plasmas. An electrostatic direct implicit 1d3v particle-in-cell code EDIPIC is developed for plane geometry simulations of Hall thruster plasmas. The EDIPIC code includes several physical effects important for Hall thrusters: collisions with neutral atoms, turbulence, and secondary electron emission. In addition, the narrow sheath regions crucial for plasma-wall interaction are resolved in simulations. The code is parallelized to achieve fast run times. <p>Inductively coupled plasmas sustained by the external RF electromagnetic field are widely used in material processing reactors and electrodeless lighting sources. In a low pressure inductive discharge, the collisionless electron motion strongly affects the absorption of the external electromagnetic waves and, via the ponderomotive force, the density profile. The linear theory of the anomalous skin effect based on the linear electron trajectories predicts a strong decrease of the ponderomotive force for warm plasmas. Particle-in-cell simulations show that the nonlinear modification of electron trajectories by the RF magnetic field partially compensates the effects of electron thermal motion. As a result, the ponderomotive force in warm collisionless plasmas is stronger than predicted by linear kinetic theory. <p>Hall thrusters, where plasma is maintained by the DC electric field crossed with the stationary magnetic field, are efficient low-thrust devices for spacecraft propulsion. The energy exchange between the plasma and the wall in Hall thrusters is enhanced by the secondary electron emission, which strongly affects electron temperature and, subsequently, thruster operation. Particle-in-cell simulations show that the effect of secondary electron emission on electron cooling in Hall thrusters is quite different from predictions of previous fluid studies. Collisionless electron motion results in a strongly anisotropic, nonmonotonic electron velocity distribution function, which is depleted in the loss cone, subsequently reducing the electron wall losses compared to Maxwellian plasmas. Secondary electrons form two beams propagating between the walls of a thruster channel in opposite radial directions. The secondary electron beams acquire additional energy in the crossed external electric and magnetic fields. The energy increment depends on both the field magnitudes and the electron flight time between the walls. <p>A new model of secondary electron emission in a bounded plasma slab, allowing for emission due to the counter-propagating secondary electron beams, is developed. It is shown that in bounded plasmas the average energy of plasma bulk electrons is far less important for the space charge saturation of the sheath than it is in purely Maxwellian plasmas. A new regime with relaxation oscillations of the sheath has been identified in simulations. Recent experimental studies of Hall thrusters indirectly support the simulation results with respect to the electron temperature saturation and the channel width effect on the thruster discharge.
5

Convergence asymptotique des niveaux de temps quasi-concaves dans un espace temps à courbure constante / Asymptomatic convergence of level sets of quasi-concave times in a space-time of constant curvature

Belraouti, Mehdi 20 June 2013 (has links)
Dans cette thèse, nous nous intéressons aux espaces temps dit globalement hyperboliques Cauchy compacts. Ce sont des espaces temps qui admettent une fonction, dite fonction temps de Cauchy, propre qui croit strictement le long des courbes causales inextensibles. Les niveaux de telles fonctions sont des hypersurfaces de type espace appelées hypersurfaces de Cauchy. La donnée d'une fonction temps définit naturellement une famille à 1-paramètres d'espaces métriques. Notre but est d'étudier le comportement asymptomatique de ces familles d'espaces métriques Il y a deux cas de figure à considérer : le premier étant le comportement asymptomatique dans le passé ; le deuxième est celui du comportement asymptomatique dans le futur. Plus de conditions géométriques sur l'espace temps et les fonctions temps à considérer seront nécessaires / In this thesis we're interested in globally hyperbolic Cauchy compact space-times. These are space-times that possess a proper function, called Cauchy time function, which ist strictly increasing along inextensible causal curves. A Cauchy time function defines naturally a 1-parameter family of metric spaces. One asks the natural and important question of the asymptomatic behaviour of this family with respect to the time : when time goes to 0 and when it goes towards infinity. Of course additional geometric condition on the space-ime and the time function will be necessary for a more appropriate study
6

Planejamento de experimentos bayesianos: aplicações em experimentos na presença de tendências lineares.

Lima, Luis Gustavo Guedes Bessa 11 January 2007 (has links)
Made available in DSpace on 2016-06-02T20:05:58Z (GMT). No. of bitstreams: 1 DissLGGBL.pdf: 694668 bytes, checksum: fbe25c1e4093e12425b0a024c8a95456 (MD5) Previous issue date: 2007-01-11 / Financiadora de Estudos e Projetos / We present a general introduction in the construction of experimental design, spe- cially a general factorial design and factorial design 2k and some Bayesian criteria in the construction of experimental design. In practice, usually the researcher can have a priori knowledge of specialists for estimated quantities from an experiment. The use of Bayesian methods can take on best results with low costs. Many Bayesian criteria in- troduced in literature are presented. One of the main applications in the experimental design construction involve the existance of linear trends with objective of verifying the best sequence of runs, specially the factorial designs with eight runs. In this disertation, we introduce some basic concepts in design of experiments and the use of the Bayesian approach to have more e¢ cient and less cost experiments. The main goal of the work, is to consider a special case of great importance in applied indistrial work: the presence of linear trend. In this case, we present a comparative study in design of experiments under the classical and Bayesian approaches. / Inicialmente apresentamos uma introdução geral sobre planejamentos de experimen- tos, em especial, o planejamento fatorial geral e o planejamento fatorial 2k, e alguns critérios Bayesianos na construção de planejamentos de experimentos. Na prática, usual- mente o pesquisador pode ter conhecimento a priori de especialistas das quantidades a serem estimadas, a partir de um experimento. O uso de métodos Bayesianos pode levar à melhores resultados com menores custos. Vários critérios Bayesianos introduzidos na liter- atura são apresentados. Algumas aplicações são consideradas para ilustrar a metodologia proposta. Uma das principais aplicações na construção de um planejamento de exper- imentos envolve a presença de tendências lineares com o objetivo de verificar a melhor seqüência possível de ensaios, em especial o planejamento fatorial com oito ensaios. Nesta dissertação, pretendemos introduzir alguns conceitos básicos em planejamen- tos de experimentos e o uso do enfoque Bayesiano que leva à experimentos com melhor eficiência e menores custos. Como objetivo principal de trabalho, vamos considerar um caso especial de grande importância nas aplicações industriais: a presença de tendên- cias lineares. Neste caso, vamos apresentar um estudo comparativo em planejamento de experimentos clássicos e planejamento de experimentos Bayesianos.

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