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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.
11

Estimativa da estatura final utilizando os cálculos matemáticos desenvolvidos por Carrea / Estimative of the final stature using the mathematical calculations developed by Carrea

Silva, Marcos André Duarte da 03 August 2012 (has links)
Algumas vezes o processo de identificação humana se depara com situações em que pouco restou do corpo humano para ser investigado, nestes casos todos os métodos identificatórios disponíveis devem ser empregados. Neste sentido, a presente pesquisa foi desenvolvida com o objetio de obter dados que facilitem o entendimento do estudo realizado por Carrea9 sobre estatura, assim como verificar a possibilidade de estimar a estatura final usando os cálculos matemáticos desenvolvidos por Carrea utilizando duas metodologias distintas. Foi realizada a mensuração da estatura em 46 brasileiros naturais da cidade de Curitiba - PR, com idade entre 22 e 37 anos divididos em três grupos: Grupo 1 formado por 24 indivíduos sem tratamento ortodôntico com os seis dentes anteriores da mandíbula em posição normal, Grupo 2A composto de 22 indivíduos com apinhamento dos dentes anteriores da mandíbula antes do tratamento ortodôntico e Grupo 2B constituído pelos mesmos 22 indivíduos do Grupo 2A, porém após o tratamento ortodôntico finalizado, e com os dentes anteriores inferiores em posição normal. A primeira metodologia avaliada, a qual foi denominada de índice de Carrea (1), utilizou as fórmulas matemáticas desenvolvidas por Carrea medindo as grandezas raio-corda e arco diretamente nos modelos ortodônticos digitalizados, já na segunda metodologia, índice de Carrea (2), foi medida a grandeza arco no modelo ortodôntico digitalizado, porém a grandeza raio-corda, foi obtida dividindo a grandeza arco por uma constante (1,0472), observada na tabela de proporção progressiva descrita por Carrea9. O índice de Carrea (2) foi aplicado em todos os indivíduos da amostra sem separá-los em grupos, uma vez que a medida raio-corda foi calculada a partir da medida arco, portanto, não importando mais a disposição dos dentes anteriores na arcada inferior. A análise descritiva da percentagem de indivíduos com altura real dentro do intervalo médio de estatura estimada aplicando-se o índice de Carrea (1), 7 apresentou se da seguinte forma: Grupo 1 - 41,7%, Grupo 2A - 72,3% e Grupo 2B - 54,5%. O estudo do tamanho do intervalo de estatura estimada mostrou o seguinte resultado: 18,9 cm para o Grupo 1, 30,6 cm para o Grupo 2A e 15,4 cm para o grupo 2B. Quando utilizado o índice de Carrea (2), verificou-se que 15,2% dos indivíduos da amostra apresentaram sua altura real dentro do intervalo de estatura estimado, 8 cm. Concluiu-se que o índice de Carrea (1) e o índice de Carrea (2), não tem aplicabilidade como método para estimar a estatura final. Não se constatou, pelo menos de maneira explícita, que o objetivo dos estudos realizados por Carrea 8,9 era o de estimar a estatura. Porém, observou-se que o mesmo teve a intenção de calcular a estatura proporcional à somatória das dimensões mésio-distais dos dentes incisivo central inferior, incisivo lateral inferior e canino inferior ipsilateral. / Sometimes the process of human identification faces situations that little of the human body remains to be investigated, in these cases all identificatory methods available must be employed. The aim of this study was to obtain data to facilitate the understanding of the Carrea`s study 9 about stature as well as check the possibility of estimating final stature using the mathematical calculations developed by Carrea using two different methodologies. Stature measurement was perfomed in 46 Brazilian from Curitiba - PR aged between 22 and 37 years and divided into three groups: Group 1 consisted of 24 subjects without orthodontic treatment and with the six mandibular anterior teeth aligned, Group 2A consists of 22 subjects with crowding of the mandibular anterior teeth before orthodontic treatment and Group 2B comprised the same 22 subjects of the Group 2A, but after orthodontic treatment and with the mandibular anterior teeth aligned. The first methodology evaluated, which was called index of Carrea (1) used the mathematical formulas developed by this author in which the radius-chord and arch measurements were obtained directly from the digitalized orthodontic models. In the second method, index of Carrea (2), the arch was measured on the digitalized orthodontic models, but the radius-chord was obtained dividing the arch measurement by a numeric constant (1.0472) observed in the table of progressive proportion described by Carrea 9. Carrea index (2) was applied in all subjects of the sample without separating them in groups, since the radius-chord was calculated from the measured arch regardless of the disposition of the lowe anterior teeth. The descriptive analysis of the percentage of subjects with real stature within the range of statures estimated applying the index Carrea (1) performed as follows: Group 1 - 41.7%, Group 2A - 72.3% and Group 2B - 54.5%. The study of the size range of the statures estimated presented the following result: 18.9 cm for the Group 1, 30.6 cm for the Group 2A and 15.4 cm for the Group 2B. Using the index Carrea (2) it was found that 15.2% of the sample had their real 9 stature within the range of the statures estimated and the size of this range was 8 cm. It was concluded that the indexes of Carrea (1) and (2) have no applicability as a method to estimate the final stature. Its not confirmed at least explicitly in the studies of Carrea that was his aim to estimate the stature. It was observed that Carrea intended to calculate the final human stature proportional to the sum of mesio-distal dimensions of lower central incisor, lower lateral incisor and lower canine ipsilateral.
12

The accuracy and reliability of plaster vs digital study models : a comparison of three different impression materials

Lands, Bradley 04 1900 (has links)
Introduction: Le but de l’étude était d’examiner l’effet des matériaux à empreintes sur la précision et la fiabilité des modèles d’études numériques. Méthodes: Vingt-cinq paires de modèles en plâtre ont été choisies au hasard parmi les dossiers de la clinique d’orthodontie de l’Université de Montréal. Une empreinte en alginate (Kromopan 100), une empreinte en substitut d’alginate (Alginot), et une empreinte en PVS (Aquasil) ont été prises de chaque arcade pour tous les patients. Les empreintes ont été envoyées chez Orthobyte pour la coulée des modèles en plâtre et la numérisation des modèles numériques. Les analyses de Bolton 6 et 12, leurs mesures constituantes, le surplomb vertical (overbite), le surplomb horizontal (overjet) et la longueur d’arcade ont été utilisés pour comparaisons. Résultats : La corrélation entre mesures répétées était de bonne à excellente pour les modèles en plâtre et pour les modèles numériques. La tendance voulait que les mesures répétées sur les modèles en plâtre furent plus fiables. Il existait des différences statistiquement significatives pour l’analyse de Bolton 12, pour la longueur d’arcade mandibulaire, et pour le chevauchement mandibulaire, ce pour tous les matériaux à empreintes. La tendance observée fut que les mesures sur les modèles en plâtre étaient plus petites pour l’analyse de Bolton 12 mais plus grandes pour la longueur d’arcade et pour le chevauchement mandibulaire. Malgré les différences statistiquement significatives trouvées, ces différences n’avaient aucune signification clinique. Conclusions : La précision et la fiabilité du logiciel pour l’analyse complète des modèles numériques sont cliniquement acceptables quand on les compare avec les résultats de l’analyse traditionnelle sur modèles en plâtre. / Introduction: The purpose of this study was to examine the effects of different impression materials on the accuracy and reliability of digital models. Methods: Models from 25 patients selected at random from the files of the Department of Orthodontics at the University of Montreal were used in this study. One alginate (Kromopan 100 alginate, Italy), 1 alginate alternative (Alginot, Kerr Dentistry, Orange, CA), and 1 PVS (Aquasil, Dentsply Caulk, Milford, DE) impression was taken of both arches of each patient and sent to Orthobyte (Othobyte Digital Technology inc., Calgary, AB) for fabrication of a plaster model and scanning for production of a digital model. The Bolton 6 and 12 analyses and their constituent measurements, overbite, overjet, and arch length were used for the comparison. Results: The repeatability of measurements using both the plaster and digital methods was good to excellent, with the plaster measurements tending to be more reliable. There were statistically significant differences in the Bolton 12 and mandibular arch length and spacing measurements for all impression materials, with the plaster models tending to give a smaller measurement for the Bolton 12 and a higher measurement for the mandibular arch length and spacing. Although statistically significant differences in some measurements were found for the reliability and validity of digital models, none was clinically significant. Conclusions: The accuracy and reliability of the software for comprehensive cast analysis is clinically acceptable and reproducible when compared with traditional plaster study model analysis.
13

Examining the taphonomic challenges to the 3D digitisation of fragmented bone

Holland, Andrew D. January 2017 (has links)
The utilisation of 3D digitisation and visualisation has grown considerably since 2008 and is becoming an increasingly useful tool for the digital documentation and metric analysis of archaeological artefacts and skeletal remains. It provides public access to rare and fragile specimens of palaeontological and palaeopathological importance whilst reducing the physical impact on these remains. Research in engineering and computer vision provides some insight into the impact of surface properties such as colour, specularity, reflectance and shape on the quality of the recorded 3D image, but within the archaeological and palaeontological disciplines comparable work has not yet been developed. If archaeology and anthropology are to provide long term reliable data from archaeological and palaeontological specimens in a way that doesn’t require repeated re-digitisation, we need to understand the impacts that the taphonomic histories of such samples have on our ability to 3D record them. Understanding the relationship of these taphonomic histories and the surface and optical properties will promote informed choices about the suitability of recording techniques. This thesis considers the taphonomic processes that affect the preservation of bone over archaeological, forensic and palaeontological timescales and the effect this has on the quality of 3D digital models. The digital refit of fragmentary bone samples is considered in relation to the effect of taphonomic alterations to bone. Conclusions regarding the key taphonomic factors and 3D digital model quality are drawn and areas of further work are identified.
14

Estimativa da estatura final utilizando os cálculos matemáticos desenvolvidos por Carrea / Estimative of the final stature using the mathematical calculations developed by Carrea

Marcos André Duarte da Silva 03 August 2012 (has links)
Algumas vezes o processo de identificação humana se depara com situações em que pouco restou do corpo humano para ser investigado, nestes casos todos os métodos identificatórios disponíveis devem ser empregados. Neste sentido, a presente pesquisa foi desenvolvida com o objetio de obter dados que facilitem o entendimento do estudo realizado por Carrea9 sobre estatura, assim como verificar a possibilidade de estimar a estatura final usando os cálculos matemáticos desenvolvidos por Carrea utilizando duas metodologias distintas. Foi realizada a mensuração da estatura em 46 brasileiros naturais da cidade de Curitiba - PR, com idade entre 22 e 37 anos divididos em três grupos: Grupo 1 formado por 24 indivíduos sem tratamento ortodôntico com os seis dentes anteriores da mandíbula em posição normal, Grupo 2A composto de 22 indivíduos com apinhamento dos dentes anteriores da mandíbula antes do tratamento ortodôntico e Grupo 2B constituído pelos mesmos 22 indivíduos do Grupo 2A, porém após o tratamento ortodôntico finalizado, e com os dentes anteriores inferiores em posição normal. A primeira metodologia avaliada, a qual foi denominada de índice de Carrea (1), utilizou as fórmulas matemáticas desenvolvidas por Carrea medindo as grandezas raio-corda e arco diretamente nos modelos ortodônticos digitalizados, já na segunda metodologia, índice de Carrea (2), foi medida a grandeza arco no modelo ortodôntico digitalizado, porém a grandeza raio-corda, foi obtida dividindo a grandeza arco por uma constante (1,0472), observada na tabela de proporção progressiva descrita por Carrea9. O índice de Carrea (2) foi aplicado em todos os indivíduos da amostra sem separá-los em grupos, uma vez que a medida raio-corda foi calculada a partir da medida arco, portanto, não importando mais a disposição dos dentes anteriores na arcada inferior. A análise descritiva da percentagem de indivíduos com altura real dentro do intervalo médio de estatura estimada aplicando-se o índice de Carrea (1), 7 apresentou se da seguinte forma: Grupo 1 - 41,7%, Grupo 2A - 72,3% e Grupo 2B - 54,5%. O estudo do tamanho do intervalo de estatura estimada mostrou o seguinte resultado: 18,9 cm para o Grupo 1, 30,6 cm para o Grupo 2A e 15,4 cm para o grupo 2B. Quando utilizado o índice de Carrea (2), verificou-se que 15,2% dos indivíduos da amostra apresentaram sua altura real dentro do intervalo de estatura estimado, 8 cm. Concluiu-se que o índice de Carrea (1) e o índice de Carrea (2), não tem aplicabilidade como método para estimar a estatura final. Não se constatou, pelo menos de maneira explícita, que o objetivo dos estudos realizados por Carrea 8,9 era o de estimar a estatura. Porém, observou-se que o mesmo teve a intenção de calcular a estatura proporcional à somatória das dimensões mésio-distais dos dentes incisivo central inferior, incisivo lateral inferior e canino inferior ipsilateral. / Sometimes the process of human identification faces situations that little of the human body remains to be investigated, in these cases all identificatory methods available must be employed. The aim of this study was to obtain data to facilitate the understanding of the Carrea`s study 9 about stature as well as check the possibility of estimating final stature using the mathematical calculations developed by Carrea using two different methodologies. Stature measurement was perfomed in 46 Brazilian from Curitiba - PR aged between 22 and 37 years and divided into three groups: Group 1 consisted of 24 subjects without orthodontic treatment and with the six mandibular anterior teeth aligned, Group 2A consists of 22 subjects with crowding of the mandibular anterior teeth before orthodontic treatment and Group 2B comprised the same 22 subjects of the Group 2A, but after orthodontic treatment and with the mandibular anterior teeth aligned. The first methodology evaluated, which was called index of Carrea (1) used the mathematical formulas developed by this author in which the radius-chord and arch measurements were obtained directly from the digitalized orthodontic models. In the second method, index of Carrea (2), the arch was measured on the digitalized orthodontic models, but the radius-chord was obtained dividing the arch measurement by a numeric constant (1.0472) observed in the table of progressive proportion described by Carrea 9. Carrea index (2) was applied in all subjects of the sample without separating them in groups, since the radius-chord was calculated from the measured arch regardless of the disposition of the lowe anterior teeth. The descriptive analysis of the percentage of subjects with real stature within the range of statures estimated applying the index Carrea (1) performed as follows: Group 1 - 41.7%, Group 2A - 72.3% and Group 2B - 54.5%. The study of the size range of the statures estimated presented the following result: 18.9 cm for the Group 1, 30.6 cm for the Group 2A and 15.4 cm for the Group 2B. Using the index Carrea (2) it was found that 15.2% of the sample had their real 9 stature within the range of the statures estimated and the size of this range was 8 cm. It was concluded that the indexes of Carrea (1) and (2) have no applicability as a method to estimate the final stature. Its not confirmed at least explicitly in the studies of Carrea that was his aim to estimate the stature. It was observed that Carrea intended to calculate the final human stature proportional to the sum of mesio-distal dimensions of lower central incisor, lower lateral incisor and lower canine ipsilateral.
15

Avaliação da quantidade de movimentação dentária com fios de níquel-titânio e aço multifilamentado na fase inicial de tratamento ortodôntico com aparelho fixo / Evaluation of the amount of tooth movement with nickel-titanium and multistrandred stainless steel wires in the initial phase of orthodontic treatment with fixed appliance

Quintão, Ana Paula Abdo 12 July 2017 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-05-15T12:12:28Z No. of bitstreams: 1 anapaulaabdoquintao.pdf: 2338216 bytes, checksum: a3e802cebaa20531b4cc4d48d68342b6 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T15:53:31Z (GMT) No. of bitstreams: 1 anapaulaabdoquintao.pdf: 2338216 bytes, checksum: a3e802cebaa20531b4cc4d48d68342b6 (MD5) / Made available in DSpace on 2017-05-17T15:53:31Z (GMT). No. of bitstreams: 1 anapaulaabdoquintao.pdf: 2338216 bytes, checksum: a3e802cebaa20531b4cc4d48d68342b6 (MD5) Previous issue date: 2017-07-12 / Este ensaio clínico retrospectivo randomizado longitudinal teve como objetivo comparar a eficácia clínica de duas ligas diferentes de fios ortodônticos (0,016 "de níquel-titânio e 0,0155" coaxial multifilamentado, utilizados para o alinhamento e nivelamento dos dentes durante 6 semanas. Avaliou-se também a quantidade de movimentação tridimensional. A tecnologia digital tem sido amplamente utilizada em modelos de gesso tridimensionais. Entretanto, há um pequeno número de ensaios clínicos. Métodos: A amostra foi composta por dois grupos de modelos de gesso obtidos de 12 pacientes jovens cada, incluindo ambos os maxilares, superior e inferior, dos pacientes. Os moldes foram digitalizados, com o escâner Maestro 3D, em dois tempos diferentes de tratamento: T1, antes da colocação do fio; e T2, 8 semanas após a sua colocação, totalizando 96 imagens digitalizadas. O programa Geometric Qualify foi utilizado para superposição de maxilares superiores e inferiores. Usando as rugas palatinas como ponto fixo para superposição das arcadas superiores, um método utilizando os modelos em oclusão foi criado pra transferir um ponto fixo das arcadas superiores para as arcadas inferiores, permitindo também, a superposição das mesmas. A quantidade precisa de movimento gerada por cada tipo de fio foi medida e visualizada através do programa CMF Application, usando linhas de contorno e mapas coloridos como ferramentas. Resultados: O fio 0,016" níquel-titânio promoveu maior quantidade de movimento dentário, que foi estatisticamente significativa, utilizando o teste de Mann-Whitney U (p <0,05). Conclusão: Os fios de níquel-titânio promoveram maior quantidade de movimentação dentária do que os fios de aço inoxidável multifilamentado. / This longitudinal retrospective randomized clinical trial aimed to compare the clinical effectiveness of two different orthodontic alloy wires (.016” nickel-titanium and .0155“ multistranded coaxial) used for dental alignment and leveling during 6 weeks. The amount of tridimensional movement was also evaluated. Digital technology has been widely used in three-dimensional dental casts. Therefore, there are a short number of clinical trials. Methods: The sample was composed by two groups of 12 young patients’ casts of both upper and lower jaws. The casts were digitalized, with Maestro 3D scanner, in two different times of treatment: T1 was before the wire was placed and T2 was 8 weeks after its placement, in a total of 96 jaw digitalized images. Geometric Qualify Software was used to generate the superimposition of upper and lower jaws. Using the palatal ruggaes as a fixed point for superimposition of the upper jaw, a method using it and the models in occlusion was created to transfer a fixed point to the lower jaws, allowing its superimposition as well. The precise quantity of movement generated by each type of wire was measured and visualized through CMF Application software by using isolines and color maps tools. Results: The .016" nickeltitanium wire promoted greater amount of tooth movement, which was statistically significant, using Mann-Whitney U test (p < 0.05). Conclusion: The nickel-titanium wires promoted a higher quantity of tooth movement than the multistranded stainless steel wire.
16

Investigations into orthodontic anchorage

Jambi, Safa Abdulsalam A. January 2014 (has links)
Background and objectives: The control of anchorage is integral to successful orthodontic treatment. The objective of this research was to undertake three related projects to evaluate methods of increasing anchorage with the aim of adding to orthodontic knowledge and improve methods of treatment delivery. Methods: Two Cochrane systematic reviews were undertaken according to the methods published in the Cochrane Handbook for Systematic Reviews of Interventions, version 5.1.0. The influence of functional appliances on tooth position and the extraction decision was performed as a retrospective study using participants from a completed multicentre randomized trial. Results: 1- Statistically and clinically significant differences were found between the mean values of distal molar movement when surgical anchorage and conventional anchorage were compared. 2- Statistically significant differences were found between the mean values of distal molar movement and mesial upper incisor movement when intraoral distalising appliances and cervical headgear were compared.3- Fixed and removable functional appliances are equally effective in anchorage preparation. The type of functional appliance and time spent in Phase I treatment influenced the amount of lower incisor proclination. Conclusions: 1- Surgical anchorage is more effective than headgear without the inherent risks and compliance issues. However, intraoral appliances used in adolescence for distalisation of upper molars do not appear to have any advantages over cervical headgear. 2- Functional appliances reduce the anchorage requirements of a case primarily by reduction of the overjet, both fixed and removable functional appliances are equally effective in obtaining this. However, fixed functional appliances result in greater lower incisor proclination than removable functional appliances. 3- The type of functional appliance (removable or fixed) does not influence the extraction decision, however, this is influenced by overall space requirements.
17

Digital models of manufacturing : with emphasis on titanium welding for early product development

Al Choueyri, Yousef, Fayazi, Mojtaba January 2019 (has links)
This thesis work is part of the BTH research lab, focusing on developing the early product development, by analyzing how to integrate the manufacturing process with the early design process. A known problem in the manufacturing industry is the knowledge gap between the designers and the manufacturing process. Where in the early stages of the product development a knowledge regarding the manufacture process is needed. This is in many cases ignored by the designers because it is commonly thought that the responsibility of selecting the manufacturing processes for a product falls upon the manufacturers, despite the fact that the manufacturing processes in reality is highly dependent upon the design choses such as materials, size, shape, finishing and tolerances of the product. To mitigate this problem a variations of product ‘team’ approaches have been used where the idea is to involve a multitude of people with the necessary experience to produce a ‘production friendly product’. Those approaches have a few drawbacks mainly the problem of finding people with the relevant experiences or that the expertise only covers the manufacturing processes already used in the organization, losing the opportunity to benefit from any alternative manufacturing process. This thesis focuses on how the welding manufacturing technic, analysis can be integrated into the design process with the help of a digital model? To improve the communications between the manufacturers and designers, two excel files were developed. The first excel file aimed at the manufacturers where they can present the specific machines used in the workshop. Focusing on specific machine and workshops instead of on the general welding method will give the designers a better understanding of the feasibility of producing their design in a specific workshop instead of focusing on a specific manufacturing method. The second excel file is aimed at calculating and comparing the weld methods where the cost and requirements are derived for general welding methods and compared with the machine specifications gathered from the manufacturers using the first excel file. To assess the excel files, a parametrized CAD model of the rear engine turbine structure was developed, and three different cases were used to evaluate the developed excel files. The values used are presented in Appendix A: Table 11–15, and were gathered from public sources. Values were also approximated using regression analysis. / Avhandlingen är en del av BTH research lab och fokuserar på det tidiga produktutvecklingsstadiet. Närmare kontrolleras hur produkttillverkningsprocessen kan integreras in i det tidiga produktutvecklingsstadiet. Ett känt problem för detta område är skillnaden på kunskapen som designer och tillverkaren besitter under det tidiga produktutvecklingsstadiet, då kunskapen om tillverkningsprocessen inte existerar. Vanligtvis tar inte produktutvecklare hänsyn till detta, eftersom ansvaret för valet av tillverkningsprocessen bedöms falla på tillverkaren. Trots att tillverkningsprocessen beror på många aspekter som bestäms under designprocessen som till exempel materialval, geometrin, efterbehandlingar och toleranser på produkten. För att minimera problemet involverar industrin en stor variation av människor med kompetens och erfarenhet, som sedan kan tillverka en produkt rätt anpassad för tillverkningsprocessen. Dock har denna lösning några nackdelar, då det kan vara svårt att hitta människor med rätt erfarenhet, men då man fokuserar på ett tillverkningssätt så kan företaget gå miste om fördelarna med alternativa tillverkningsprocesser. Denna avhandling fokuserar på hur analysen av svetstillverkningstekniken kan integreras in i designprocessen med hjälp av en digital modell. För att förbättra kommunikationen mellan tillverkare och designer har 2 Excel filer utvecklats. Den första Excel filen är riktat mot tillverkarna där dem kan nämna maskinerna som finns tillgängliga i deras verkstad. Den andra Excel filen är till för att kunna göra en kostnadskalkyl och jämföra dem olika tillverkningsmetoderna med hjälp av maskinspecifikationerna som fanns presenterade i den första Excel filen. För att utvärdera Excel filerna, har en parametrisk CAD modell skapats och 3 fall har använts för att testa de utvecklade CAD modellera. Värdena som använts i detta examensarbete finns i Appendix A: Table 11–15 och är hämtade från allmänt tillgängliga källor. Värden uppskattades också med hjälp av regressionsanalyser.
18

Examining the taphonomic challenges to the 3D digitisation of fragmented bone

Holland, Andrew D. January 2017 (has links)
The utilisation of 3D digitisation and visualisation has grown considerably since 2008 and is becoming an increasingly useful tool for the digital documentation and metric analysis of archaeological artefacts and skeletal remains. It provides public access to rare and fragile specimens of palaeontological and palaeopathological importance whilst reducing the physical impact on these remains. Research in engineering and computer vision provides some insight into the impact of surface properties such as colour, specularity, reflectance and shape on the quality of the recorded 3D image, but within the archaeological and palaeontological disciplines comparable work has not yet been developed. If archaeology and anthropology are to provide long term reliable data from archaeological and palaeontological specimens in a way that doesn’t require repeated re-digitisation, we need to understand the impacts that the taphonomic histories of such samples have on our ability to 3D record them. Understanding the relationship of these taphonomic histories and the surface and optical properties will promote informed choices about the suitability of recording techniques. This thesis considers the taphonomic processes that affect the preservation of bone over archaeological, forensic and palaeontological timescales and the effect this has on the quality of 3D digital models. The digital refit of fragmentary bone samples is considered in relation to the effect of taphonomic alterations to bone. Conclusions regarding the key taphonomic factors and 3D digital model quality are drawn and areas of further work are identified. / Arts and Humanities Research Council
19

Validité, fiabilité et reproductibilité des modèles digitaux obtenus avec iTero (Align Technology) et Unitek TMP Digital (3M) en comparaison avec les modèles de plâtre

Péloquin, Vincent-Claude 06 1900 (has links)
Objectif: L'objectif primaire de cette étude était d'évaluer la validité, la fiabilité et la reproductibilité des mesures dentaires obtenues sur les modèles digitaux iTero (Align Technology, San Jose, Californie) et Unitek TMP Digital (3M, Monrovia, Californie) en comparaison avec celles obtenues sur les modèles de plâtre (gold standard). L'objectif secondaire était de comparer les deux différents matériaux à empreinte (l'alginate et le polyvinylsiloxane-PVS) afin de déterminer si le choix du matériau affectait la précision des mesures. Méthodes: Le premier volet de l'étude impliquait les modèles digitaux Unitek et iTero, obtenus à partir de 25 paires de modèles de plâtre choisis de façon randomisée et provenant de la pratique privée d'un des co-auteurs. Des empreintes d'alginate et de PVS ont été prises sur les modèles de plâtre et numérisées par le scanner Unitek. Les modèles ont ensuite été numérisés avec le scanner iTero. Le deuxième volet de l'étude cherchait à comparer les modèles digitaux iTero (numérisation intra-orale) avec les modèles de plâtre (empreintes d'alginate et de PVS) obtenus à partir de 25 patients de la clinique d'orthodontie de l'Université de Montréal ayant besoin d'un traitement orthodontique. Dans les deux volets de l'étude, deux auteurs ont pris les mesures suivantes sur les différents modèles: largeur mésio-distale de chaque dent de la première molaire à l'autre première molaire, le périmètre d'arcade, les distances intermolaire et intercanine, le surplomb vertical et le surplomb horizontal. Les ratios et excès Bolton 6 et 12, l'espace requis et les différentiels d'espace au maxillaire et à la mandibule, ont été calculés. Résultats: La fiabilité (ICC) entre les modèles digitaux (Unitek et iTero) et les modèles de plâtre était bonne à excellente pour toutes les mesures [ICC=0,762–0,998], et la fiabilité entre les deux matériaux à empreinte était excellente [ICC=0,947–0,996]. Dans les deux volets de l'étude, les mesures faites sur les modèles iTero étaient généralement plus grandes que celles faites sur les modèles de plâtre. Les plus grandes différences moyennes pour la comparaison iTero-plâtre étaient trouvées au niveau de l'espace disponible au maxillaire et à la mandibule (systématiquement plus grande pour cette variable), soit 2,24 mm et 2,02 mm respectivement dans le premier volet, et 1,17 mm et 1,39 mm respectivement dans le deuxième volet. Les différences étaient considérées cliniquement non significatives pour toutes les variables. La reproductibilité intra-examinateur était bonne à excellente pour les modèles de plâtre et les modèles digitaux, à l'exception du différentiel d'espace à la mandibule pour les modèles Unitek [ICC=0,690-0,692]. La reproductibilité inter-examinateur était bonne à excellente pour les modèles de plâtre et les modèles digitaux dans les deux volets de l'étude, mais acceptable à modérée pour les modèles Unitek au niveau des analyses Bolton 6 et 12, et des différentiels d'espace au maxillaire et à la mandibule [ICC=0,362-0,548]. Conclusions: La précision et la fiabilité des mesures dentaires faites sur les modèles digitaux Unitek et iTero étaient cliniquement acceptables et reproductibles en comparaison avec les celles faites sur les modèles de plâtre. Le choix de matériel à empreinte entre l'alginate et le PVS n'affectait pas la précision des mesures. Cette étude semble démontrer que les modèles digitaux Unitek et iTero, utilisés avec leur logiciel respectif, sont une alternative fiable et reproductible aux modèles de plâtre pour le diagnostic et l’analyse des modèles orthodontiques. / Objective: The primary objective of this study was to evaluate the validity, reliability and reproducibility of dental measurements obtained on digital models produced by iTero (Align Technology, San Jose, California) and by Unitek TMP Digital (3M, Monrovia, California) in comparison with those obtained on plaster models (gold standard). The secondary objective was to compare two different impression materials (alginate and polyvinylsiloxane-PVS) to determine whether the material used affects accuracy of the measurements. Methods: The first part of the study involved Unitek and iTero digital models, which were all obtained from 25 pairs of plaster models randomly selected from one of the co-author's private practice. Alginate and PVS impressions were taken on plaster models and were scanned by the Unitek scanner. The same models were then scanned with the iTero scanner. The second part of the study sought to compare iTero digital models (intraoral scans) with plaster models (alginate and PVS impressions) taken on 25 patients requiring treatment from the Orthodontic clinic of the University of Montreal. In both parts of the study, two authors took the following measurements on the different models: mesio-distal width of each tooth from first molar to the other first molar, intermolar and intercanine distances, overbite and overjet. Bolton 6 and 12 ratios and excesses, maxillary and mandibular space available and required were also calculated in order to determine space differentials. Results: A good to excellent reliability (ICC) was found for all measurements when comparing digital (Unitek and iTero) and plaster models [ICC=0.762–0.998], and excellent reliability when comparing both impression materials [ICC=0.947–0.996]. In the two parts of the study, measurements on iTero models were generally larger than on plaster models. Highest mean differences for iTero-plaster were found for maxillary space available and mandibular space available (systematically larger for that variable): 2.24 mm and 2.02 mm respectively in the first part of the study, 1.17 mm and 1.39 mm respectively in the second part. Differences were considered clinically insignificant for all variables. Intraexaminer reproducibility was good to excellent for plaster and digital models, except for mandibular space differential on Unitek models [ICC=0.690-0.692]. Interexaminer reproducibility was good to excellent for plaster and digital models in both parts of study, but fair to moderate for Unitek models regarding Bolton 6 and 12, and maxillary and mandibular space differentials [ICC=0.362-0.548]. Conclusions: The accuracy and reliability of dental measurements done on Unitek and iTero digital models were clinically acceptable and reproducible when compared with measurements done on traditional plaster models. The choice of impression material between alginate and PVS did not affect accuracy of the measurements. This study tends to indicate that Unitek and iTero digital models examined with their associated software can be reliably used for orthodontic cast analysis and diagnosis.
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Modelos digitais: o ensino de sistemas estruturais para Arquitetura e Urbanismo / Digital models: teaching structural systems to Architecture and Urbanism

Cunto, Ivanóe De 04 March 2016 (has links)
A partir da grande complexidade e dos vários fatores inerentes ao processo de projeto em Arquitetura e Urbanismo, a presente tese busca analisar se na formação do Arquiteto, as escolas e professores estão preparados para enfrentar essa realidade pelo ponto de vista do conhecimento estrutural. Para tanto a presente tese analisou o resultado de trabalhos de TFG, das disciplinas de introdução aos Sistemas Estruturais e os procedimentos adotados por seus professores, de duas escolas de Arquitetura e Urbanismo no Paraná. A primeira é uma Universidade pública e a outra um Centro Universitário particular. A busca pela resposta a essa questão, demonstra que todo o processo de ensino de Arquitetura, requer mudanças significativas. Passando por atualizações nos currículos e nos procedimentos adotados por professores, em face a defasagem percebida durante a pesquisa. A pesquisa propõe inicialmente uma nova sistemática aliada ao cálculo, propiciando que o aluno tenha primeiramente uma visualização real dos diversos Sistemas Estruturais, apoiado em modelos digitais de edifícios reais. Esse novo procedimento foi aplicado aos alunos dessas disciplinas iniciais com resultados positivos quanto ao conhecimento adquirido. Nos períodos seguintes, em acompanhamento a um grupo desses alunos, verificou-se que os trabalhos elaborados nas disciplinas seguintes de Projeto Arquitetônico, não se utilizavam desse conhecimento adquirido em seus trabalhos. Uma pesquisa feita com os professores de Projeto mostrou a dificuldade que os próprios professores enfrentavam com orientações nas questões estruturais. Para tanto, além desse procedimento inicial de uso de modelos digitais, novas mudanças se fazem necessárias também no currículo e na proposta de trabalho de cada uma das instituições pesquisadas, objetivando que os conhecimentos adquiridos com o uso de modelos digitais pudessem ser permanentes. Como embasamento as mudanças de posicionamento pedagógico e curricular com o uso de modelos digitais, a tese foi construída sob dois pontos fundamentais. Primeiramente a Teoria das Inteligências Múltiplas do psicólogo americano Howard Gardner, focando na Inteligência Espacial e a Taxonomia de Bloom, elaborada por Benjamim Samuel Bloom, sobre o Domínio Cognitivo, que são aplicadas para verificação da aprendizagem através da analisa de seis categorias hierarquicamente separadas, da mais simples ao de maior complexidade, que envolve conhecimento, compreensão, aplicação, análise, síntese e avaliação. Como resultado a essa pesquisa, chegou-se à conclusão de que os cursos pesquisados devem prover o conhecimento de Sistemas Estruturais, através de projetos pedagógicos atualizados e mais eficientes, aliados a professores comprometidos com as modernas metodologias pedagógicas, visando uma ampla compreensão dos conteúdos de suas disciplinas por parte dos alunos e buscando que o conhecimento estrutural adquirido num primeiro momento, seja efetivamente praticado nas demais disciplinas. / From the great complexity and the various factors inherent in the design process in Architecture and Urbanism, this thesis seeks to analyze whether the architectural education, schools and teachers are prepared to face this reality from the point of view of structural knowledge. For this purpose, this thesis analyzed the result of TFG work, introduction of disciplines to structural systems and procedures adopted by their teachers, two schools of Architecture and Urbanism of Londrina in Parana. The first is a public university and the other a private university center. The search for the answer to this question show that the whole architecture of teaching process requires significant changes. Undergoing upgrades in the curricula and procedures adopted by teachers, given the lag perceived while searching. The search initially proposes a new system combined with calculation, enabling the student to first have a real view of various systems supported by digital models of real buildings. This new procedure was applied to the students of these disciplines with initial positive results regarding the acquired knowledge. In subsequent periods, in monitoring a group of these students, it was found that the works carried out in the following disciplines of Architectural Design, not used this knowledge acquired in their work. A survey of the project teachers showed the difficulty that teachers themselves faced with guidelines on structural issues. For that, beyond this initial procedure using digital models, new changes should also happen in curriculum and work proposal of each of the institutions surveyed, aiming that the knowledge acquired with the use of digital models could be permanent. As basis the changes in teaching and curriculum positioning with the use of digital models, the thesis was built on two fundamental points. First, the Theory of Multiple Intelligences of the American Howard Gardner psychologist, focusing on the Space Intelligence and Bloom\'s Taxonomy, developed by Benjamin Samuel Bloom, on the Cognitive Domain, which are applied for verification of learning through analyzes six hierarchically separate categories of the simplest to the most complex, involving knowledge, comprehension, application, analysis, synthesis and evaluation. As a result to this research, we came to the conclusion that the surveyed courses should provide the structural systems knowledge through upgraded and more efficient educational projects, together with teachers committed to the modern teaching methods, aimed at a broad understanding of the contents of their disciplines by students and seeking the structural knowledge gained at first, is actually practiced in other disciplines.

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