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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.
111

\"Articulador virtual\" Precisão dos contatos oclusais observados em modelos virtuais em comparação com modelos reais / \"Virtual articulator\" Accuracy of occlus contacts observed in virtual models compared to real models

Merino, Ivan Ricardo Garcia 28 November 2018 (has links)
Objetivo: O objetivo do presente estudo foi avaliar in vitro a precisão dos contatos oclusais obtidos em pacientes dentados por meio do articulador virtual. Materiais e Métodos: Trinta e seis modelos foram obtidos de pacientes dentados e montados em articulador semi ajustavel (ASA) A7 Plus (Bio-art). O registo intermaxilar foi realizado utilizando silicone occlufast Rock (Zhermack). Após a montagem em articulador, os contatos oclusais foram demarcados nos modelos de gesso com carbono de 20 ?m de espessura (AccuFilm), os quais foram utilizados como valores de referência. Com o intuito de obter modelos virtuais, os modelos de gesso foram então digitalizados por meio de um scanner laboratorial (Dental Wings 7, Straumann). Realizou-se a calibração do articulador virtual de acordo com as recomendações do fabricante e os contatos oclusais nos modelos digitais foram obtidos automaticamente por meio do respectivo software. A análise quantitativa dos contatos oclusais foi realizada independentemente por dois examinadores, de forma que cada examinador repetiu a contagem duas vezes com um intervalo de 48h entre as medições. A concordância intra e inter examinadores, assim como a correlação entre os contatos oclusais obtidos em modelos virtuais e modelos de gesso foram avaliados estatisticamente por meio do coeficiente Kappa com nível de significância ? = 5%. A concordância intra-examinador foi de 0.93 a 0.98 (p < 0,001), enquanto que a concordância entre os examinadores variou entre 0.61 a 0.67 (p < 0,001) para ambos modelos virtuais e de gesso. Os contatos obtidos em modelos virtuais e modelos de gesso convencionais apresentaram uma concordância entre 0.52 a 0.55 (p < 0,001). Conclusão: Dentre as limitações apresentadas pelo presente estudo, foi possível concluir que o articulador virtual apresentou uma precisão moderada para a determinação dos contatos oclusais em pacientes dentados. / Objective: The objective of the study was to evaluate in vitro the accuracy of occlusal contacts obtained in patients through the virtual articulator. Materials and Methods: Thirty-six models were obtained from patients and mounted on a semi-adjustable articulator (ASA) A7 Plus (Bio-art). The intermaxillary registration was performed using silicone occlufast rock (Zhermack). After mounting in the articulator, the occlusal contacts were delimited in the 20 ?m thick carbon film (AccuFilm), which were used as reference values. In order to obtain virtual models, the gypsum models were scanned with a laboratory scanner (Dental Wings 7, Straumann). The virtual articulator calibration was performed according to the manufacturer\'s recommendations and the occlusal contacts in the digital models were obtained automatically through the corresponding software. Results: The quantitative analysis of the occlusal contacts was performed independently by two examiners, so that each examiner repeated the count twice with a 48h interval between measurements. The intra and inter-examiner agreement, as well as the correlation between the occlusal contacts obtained in virtual models and gypsum models were statistically evaluated using the Kappa coefficient with significance level ?=5%. The intra-examiner agreement was 0.93 to 0.98 (p <0.001), whereas the agreement between the examiners ranged from 0.61 to 0.67 (p <0.001) for both virtual and gyspsum models. The contacts obtained in virtual models and conventional gypsum models showed an agreement between 0.52 and 0.55 (p <0.001). Conclusion: Considering the limitations of the present study, it was possible to conclude that the virtual articulator showed a moderate precision for the determination of occlusal contacts in patients.
112

Propriedades mecânicas e caracterização intrínseca de zircônia experimental para uso em sistemas CAD/CAM / Mechanical and intrinsic characterization of an experimental zirconia composition

Ramos, Carla Müller 07 March 2013 (has links)
O objetivo deste estudo foi avaliar as propriedades mecânicas e as características intrínsecas de uma zircônia tetragonal policristalina parcialmente estabilizada por ítria (Y-TZP) experimental comparada a outras três Y-TZPs comercialmente disponíveis, a partir de blocos para sistema CAD/CAM. Os grupos foram: Y-TZP Experimental (ZE), Zirconcad (ZCA), IPS e.max ZirCad (ZMAX) e In Ceram YZ (ZYZ). Resistência flexural: 120 espécimes foram construídos para cada grupo (n=30) e submetidos ao ensaio de flexão em três pontos com velocidade de 0,5mm/min, de acordo com a ISO 6872. ANOVA a um critério foi utilizada para análise de diferenças significantes entre os grupos (&#x3B1;=0,05). Para a caracterização da resistência e longevidade dos materiais estudados, utilizou-se a análise estatística de Weibull por meio de dois parâmetros: o módulo de Weibull (m) e a resistência característica (&#x3B4;0). Análise Fractográfica: a superfície da fratura dos espécimes foi analisada pelo microscópio eletrônico de varredura (MEV) sendo que o tamanho do defeito crítico (c) e a tenacidade à fratura (KIC) foi estimado por análise fractográfica quantitativa e sua caracterização por meio de análise fractográfica qualitativa. Espectroscopia Micro Raman: as fases da estrutura cristalina das diferentes Y-TZP foram identificadas por meio da detecção das bandas características. Houve diferença significativa (p <0,05) na resistência à flexão entre ZCA, que apresentou os menores valores, em comparação com ZE, ZMAX e ZYZ, que, por sua vez, foram semelhantes entre si. As superfícies fraturadas de todos os espécimes apresentaram marcas fractográficas características, sendo observada na superfície de ZCA uma maior quantidade de defeitos. Os valores de tenacidade à fratura de ZE foram significantemente diferente apenas para ZCA. Todos os materiais apresentaram as bandas características das fases tetragonal e monoclínica da Y-TZP. ZE mostrou-se semelhante em suas propriedades mecânicas e microestrutura às ZMAX e ZYZ, apresentando-se como um material promissor para uso em sistema CAD/CAM. ZCA apresentou os menores valores de resistência flexural e tenacidade à fratura o que sugere que a quantidade e distribuição de defeitos tem efeito sobre seu comportamento mecânico. / The aim of this study was to evaluate the mechanical properties and the intrinsic characteristics of an experimental yttrium tetragonal zirconia partially stabilized (Y-TZP) compared the other three Y-TZPs commercially available starting block for CAD/CAM system. The groups were: Experimental Zirconia (ZE), Zirconcad (ZCA), IPS e.max ZirCad (ZMAX) and In Ceram YZ (ZYZ). Flexural strength: 120 specimens were constructed for each group (n=30) and subjected to bending test at three points crosshead speed of 0.5mm/min, according to ISO 6872. ANOVA test was used to analyze significant differences between groups (&#x3B1;=0.05). To characterize the strength and longevity of the materials, the Weibull statistical analysis by two parameters were used: the Weibull modulus (m) and the characteristic strength (&#x3B4;0). Fractographic analyzes: the fracture surface of the specimens was analyzed by scanning electron microscope (SEM) and the size of the critical defect (c) and fracture toughness (KIC) was estimated by quantitative fractographic analysis and characterization through qualitative analysis. Micro Raman spectroscopy: phases of crystalline structures of different Y-TZP were identified by detecting the characteristic bands. Statistically significant (p <0.05) in flexural strength between ZCA, which had the lowest values compared with ZE, ZMAX and ZYZ, which in turn were similar. The fractured surfaces of all specimens showed similar fractographics characteristics and values of fracture toughness for ZE were significant difference only for ZCA. All materials showed the characteristic bands of tetragonal and monoclinic phases of zirconia. ZE were similar in its mechanical properties and intrinsic, which suggests that material capable of being used for the system CAD/CAM and applied clinically as framework.
113

Modelando o futuro: a evolução do uso de tecnologias digitais no desenvolvimento de projetos de arquitetura / Shapping the future: the evolution of digital technology design in architecture

Silvio Sguizzardi 13 May 2011 (has links)
A pesquisa aborda processos criativos e produtivos da arquitetura contemporânea, a partir da história do desenvolvimento tecnológico da computação gráfica e sua influência sobre a atividade profissional do arquiteto. Baseada na análise projetual, de forma a explicitar a problemática colocada, toma como estudos de caso três projetos desenvolvidos em diferentes momentos dessa evolução: a Casa da Ópera de Sidney, na Austrália; o pavilhão H2Oexpo na ilha de Neeltje Jans, Holanda; e, o Museu Mercedes-Benz em Stuttgart, Alemanha. Através de uma análise crítica, procuramos entender as relações do uso de computadores no desenvolvimento e construção destes projetos. Para cada caso, foram analisadas as técnicas empregadas, os benefícios conquistados e inovações proporcionadas, bem como, as dificuldades, limitações e os desafios enfrentados, desde o início do desenvolvimento do projeto, ao término da execução da edificação. A leitura integral e objetiva do objeto baseia-se em acervo documental, material bibliográfico e no discurso e posicionamento de profissionais envolvidos, visando à compreensão da riqueza e diversidade do tema. O trabalho pretende dar uma contribuição ao entendimento desta relação, colaborando também para o estudos de questões projetuais ligadas as novas mídias, como forma de estabelecer uma base de conhecimento para a reflexão a respeito do uso de ferramentas da computação gráfica no universo arquitetônico. / With the history of the graphic computation technological development and its influence on the architect\'s professional activity as the starting point, the present research addresses the creative and productive processes of contemporary architecture. Based on the project analysis as a way of explaining the problem being presented, three projects developed at different times along this evolution are presented as case studies: the Sydney Opera House, Australia; the H2Oexpo Pavilion in the island of Neeltje Jans, Netherlands; the Mercedes-Benz Museum in Stuttgart, Germany. By using a critical analysis we try to understand the relations in the use of computers in the development and building of these projects. The analysis of each case included the techniques that were used, the benefits obtained and innovations provided, as well as the difficulties, limitations and challenges that were faced from the very beginning of the project development until the building was constructed. In order to better understand the wealth and diversity of the theme, the collection of documents, bibliography and statements and positioning of the professionals involved were used to obtain a full and objective reading of the object. The present work was designed to bring a contribution to understand this relation, cooperating with the study of project issues related to the new media, as a way to establish a knowledge foundation to reflect on the use of graphic computation tools in the architectural universe.
114

Implementation of user-defined features in web-based CAD applications

Kandala, Tarun January 2009 (has links)
Computer-aided Design (CAD) and Computer-aided Manufacturing (CAM) play an important role during the design and production phase of a product. CAD allows for generation of two and three-dimensional models of the product with the help of solid modelers and CAM allows for production planning of the product using tools such as a CAM package. Both CAD and CAM tools are highly specialized in nature and at the same time expensive to own. Large industries can afford to own such systems and experts to operate them but small and custom product industries cannot afford these benefits due to high design and manufacturing costs involved and complexity involved in using these systems. This has led to less popularity of CAD and CAM systems in custom product industries. A web based design tool can offer the functionality of a CAD system to custom product industries by allowing them to create and design three-dimensional models over the web. This method helps in simplifying the complexity involved in solid modeling by automating the commonly performed design operations using design algorithms. At the same time a web based manufacturing tool can allow for automatic generation of tool-paths for machining using a CNC machine. Although a web based design tool offers the required benefits to custom product industries, offering just the functionality of a CAD system may not be useful to the users of the web-based system who are usually carvers and artisans with minimal or no knowledge of CAD. An alternative method and its implementation are presented in this thesis. The method allows for creating user-defined parametric features using simple tools that can be offered in a web based application. The system takes advantage of the built-in API tools in a solid modeler and advanced web-based technologies to integrate them into a simple and easy to use web based design system. Identification of key elements in designing user-defined features and a framework for implementing them are discussed. Also different types of user-defined features that can be offered in a web application with examples of their implementation in a real world application for designing custom wooden signs are presented.
115

Implementation of user-defined features in web-based CAD applications

Kandala, Tarun January 2009 (has links)
Computer-aided Design (CAD) and Computer-aided Manufacturing (CAM) play an important role during the design and production phase of a product. CAD allows for generation of two and three-dimensional models of the product with the help of solid modelers and CAM allows for production planning of the product using tools such as a CAM package. Both CAD and CAM tools are highly specialized in nature and at the same time expensive to own. Large industries can afford to own such systems and experts to operate them but small and custom product industries cannot afford these benefits due to high design and manufacturing costs involved and complexity involved in using these systems. This has led to less popularity of CAD and CAM systems in custom product industries. A web based design tool can offer the functionality of a CAD system to custom product industries by allowing them to create and design three-dimensional models over the web. This method helps in simplifying the complexity involved in solid modeling by automating the commonly performed design operations using design algorithms. At the same time a web based manufacturing tool can allow for automatic generation of tool-paths for machining using a CNC machine. Although a web based design tool offers the required benefits to custom product industries, offering just the functionality of a CAD system may not be useful to the users of the web-based system who are usually carvers and artisans with minimal or no knowledge of CAD. An alternative method and its implementation are presented in this thesis. The method allows for creating user-defined parametric features using simple tools that can be offered in a web based application. The system takes advantage of the built-in API tools in a solid modeler and advanced web-based technologies to integrate them into a simple and easy to use web based design system. Identification of key elements in designing user-defined features and a framework for implementing them are discussed. Also different types of user-defined features that can be offered in a web application with examples of their implementation in a real world application for designing custom wooden signs are presented.
116

Energisimulering av byggnadertidigt i projekteringsfasen : En utvärdering av Energy Analysis som verktyg för hållbar byggnadsdesign / Energy simulation of buildings in an early design phase : An evaluation of Energy Analysis as a tool for sustainable building design

Knutsson, Tobias January 2015 (has links)
Dagens samhälle står idag inför en stor utmaning, nämligen att minska dess påverkan påmiljön. EU har satt upp riktlinjer mot en mer hållbar utveckling, vilket Sverige beslutat attfölja, där ett mål varit att energianvändningen 2020 ska ha minskat med 20 % jämfört med år2008. År 2021 införs krav på att alla nybyggnationer minst ska uppfylla näranollenergihuskrav.Detta medför ett större ansvar på projektörer att skapa underlag förenergieffektivare byggnader.Den tidiga designprocessen av byggnader kännetecknas av en initiativrik process där mångabeslut fattas på kort tid. De tidiga besluten som berör byggnadsutformningen har enbetydande roll för hur stora energibehov den färdiga produkten kommer att få. Energibehovetpåverkar både byggnadens livscykelkostnad och dess miljöpåverkan. Den här studien ärinriktad på energisimuleringar tidigt i projekteringsprocessen vars syfte är att skapadesigndrivande underlag till beslut rörande byggnadsutformning.Autodesk Revit har ett integrerat verktyg, Energy Analysis, som gör energisimuleringar avBIM-modellen i programmet. Verktyget är framtaget för att göra snabba energisimuleringarsom ska fungera som beslutsunderlag vid projektering mot hållbara byggnadsdesigner. Måletmed studien var att kartlägga beräkningarnas tillförlitlighet och resultatens användbarhet försvenska arkitekter. Utifrån en CAD-fil på ett hus från Klara arkitektbyrå gjordes simuleringari Energy Analysis som jämfördes med samma hus skapat Strusofts VIP-Energy.Resultaten visar att programmen redovisar olika utdata där vissa ej är jämförbara. Jämförelserav transmissionen i de båda programmen visar dock att beräkningsmotorn i Energy Analysisger rimliga resultat. Programmen räknar förhållandevis lika på solinstrålning genom fönster,dock finns det en svaghet hos Energy Analysis när de räknar på fönster med solskydd.Av resultaten dras en slutsats att Energy Analysis gör tillräckligt noggranna beräkningar föratt kunna användas tidigt i projekteringen. Verktyget behöver dock utvecklas och anpassa enversion för svenska förhållanden och normer för att det ska bli användbart i Sverige, vilketredovisas i ett förslag till produktutveckling i rapporten. / Today's society is facing a major challenge, namely to reduce its impact on the environment.The EU has set guidelines towards a more sustainable development, something in whichSweden has decided to comply; where the goal has been to minimize energy consumptionwith 20 % until 2020 compared to the consumption in 2008. In 2021, a requirement will beintroduced. It says that all new buildings in the EA must be “Nearly zero energy buildings” atleast. This implies a greater responsibility on the drafters to create the basis for energyefficient buildings.The early design process of buildings is characterized by a proactive process where manydecisions are made during a short amount time. Early decisions taken regarding the design ofa building affects its total need of energy when the house is put into use. Energy demandsaffects both the building life cycle cost and environmental impact. This study focuses onenergy simulations early in the design process that aims to create design driven basis fordecisions regarding building design.Autodesk Revit has an integrated tool, Energy Analysis, which allows energy simulations ofthe BIM model in the program. The tool is designed to make quick energy simulations thatcan provide a basis for planning the sustainable building designs. The goal of the study was toidentify the reliability of the calculations and usefulness of the results for Swedish architects.Based on a CAD file of a house from Klara arkitketbyrå(architectural firm) simulations weremade in Energy Analysis and then compared to simulations in StruSoft´s VIP Energy.The results show that the programs present different outputs in which some are notcomparable. Comparisons of conductivity in both of the programs show that the calculationengine in the Energy Analysis provides reasonable results. The programs estimate the solarradiation through the windows relatively similar; however, there is a weakness in the EnergyAnalysis as to how it calculates when the window is shaded by sunshields.By the results a conclusion has been drawn that the Energy Analysis allows sufficientlyaccurate calculations to be used early in the design process. The tool needs to be developedand customize a version for Swedish conditions and standards for it to be useful in Sweden, asreported in a suggestion for product development in the report.
117

Verbindung von Design und Konstruktion in der textilen Konfektion unter Anwendung von CAE

Krzywinski, Sybille January 2005 (has links)
Zugl.: Dresden, Techn. Univ., Habil.-Schr., 2005
118

Rechnerintegrierte wissensbasierte Form- und Lagetolerierung /

Yin, Xiangdong. January 1998 (has links)
Universiẗat-Gesamthochsch., Diss.--Paderborn, 1998.
119

Propriedades mecânicas e caracterização intrínseca de zircônia experimental para uso em sistemas CAD/CAM / Mechanical and intrinsic characterization of an experimental zirconia composition

Carla Müller Ramos 07 March 2013 (has links)
O objetivo deste estudo foi avaliar as propriedades mecânicas e as características intrínsecas de uma zircônia tetragonal policristalina parcialmente estabilizada por ítria (Y-TZP) experimental comparada a outras três Y-TZPs comercialmente disponíveis, a partir de blocos para sistema CAD/CAM. Os grupos foram: Y-TZP Experimental (ZE), Zirconcad (ZCA), IPS e.max ZirCad (ZMAX) e In Ceram YZ (ZYZ). Resistência flexural: 120 espécimes foram construídos para cada grupo (n=30) e submetidos ao ensaio de flexão em três pontos com velocidade de 0,5mm/min, de acordo com a ISO 6872. ANOVA a um critério foi utilizada para análise de diferenças significantes entre os grupos (&#x3B1;=0,05). Para a caracterização da resistência e longevidade dos materiais estudados, utilizou-se a análise estatística de Weibull por meio de dois parâmetros: o módulo de Weibull (m) e a resistência característica (&#x3B4;0). Análise Fractográfica: a superfície da fratura dos espécimes foi analisada pelo microscópio eletrônico de varredura (MEV) sendo que o tamanho do defeito crítico (c) e a tenacidade à fratura (KIC) foi estimado por análise fractográfica quantitativa e sua caracterização por meio de análise fractográfica qualitativa. Espectroscopia Micro Raman: as fases da estrutura cristalina das diferentes Y-TZP foram identificadas por meio da detecção das bandas características. Houve diferença significativa (p <0,05) na resistência à flexão entre ZCA, que apresentou os menores valores, em comparação com ZE, ZMAX e ZYZ, que, por sua vez, foram semelhantes entre si. As superfícies fraturadas de todos os espécimes apresentaram marcas fractográficas características, sendo observada na superfície de ZCA uma maior quantidade de defeitos. Os valores de tenacidade à fratura de ZE foram significantemente diferente apenas para ZCA. Todos os materiais apresentaram as bandas características das fases tetragonal e monoclínica da Y-TZP. ZE mostrou-se semelhante em suas propriedades mecânicas e microestrutura às ZMAX e ZYZ, apresentando-se como um material promissor para uso em sistema CAD/CAM. ZCA apresentou os menores valores de resistência flexural e tenacidade à fratura o que sugere que a quantidade e distribuição de defeitos tem efeito sobre seu comportamento mecânico. / The aim of this study was to evaluate the mechanical properties and the intrinsic characteristics of an experimental yttrium tetragonal zirconia partially stabilized (Y-TZP) compared the other three Y-TZPs commercially available starting block for CAD/CAM system. The groups were: Experimental Zirconia (ZE), Zirconcad (ZCA), IPS e.max ZirCad (ZMAX) and In Ceram YZ (ZYZ). Flexural strength: 120 specimens were constructed for each group (n=30) and subjected to bending test at three points crosshead speed of 0.5mm/min, according to ISO 6872. ANOVA test was used to analyze significant differences between groups (&#x3B1;=0.05). To characterize the strength and longevity of the materials, the Weibull statistical analysis by two parameters were used: the Weibull modulus (m) and the characteristic strength (&#x3B4;0). Fractographic analyzes: the fracture surface of the specimens was analyzed by scanning electron microscope (SEM) and the size of the critical defect (c) and fracture toughness (KIC) was estimated by quantitative fractographic analysis and characterization through qualitative analysis. Micro Raman spectroscopy: phases of crystalline structures of different Y-TZP were identified by detecting the characteristic bands. Statistically significant (p <0.05) in flexural strength between ZCA, which had the lowest values compared with ZE, ZMAX and ZYZ, which in turn were similar. The fractured surfaces of all specimens showed similar fractographics characteristics and values of fracture toughness for ZE were significant difference only for ZCA. All materials showed the characteristic bands of tetragonal and monoclinic phases of zirconia. ZE were similar in its mechanical properties and intrinsic, which suggests that material capable of being used for the system CAD/CAM and applied clinically as framework.
120

A utilização de computadores no projeto do edifício: conceitos e perspectivas. / Use of computers in building design: concepts and perspectives.

Francisco Ferreira Cardoso 12 September 1986 (has links)
O computador vem ocupando atualmente um papel de crescente destaque na vida do homem moderno. Nesse contexto, também a área de projeto e, mais particularmente, a do projeto de edifícios, encontram nele uma ferramenta de inestimável valor. Seu atual nível de utilização nesse setor, no entanto, não tem se aproveitado de todo o potencial oferecido. Um dos motivos que justificam tal fato está no desconhecimento, por parte dos projetistas, das reais possibilidades de emprego dos computadores na área do projeto de edifícios. Nesse sentido, o objetivo dessa Dissertação é contribuir para a organização dos conceitos necessários a tais empregos, bem como montar um painel sobre as perspectivas de utilização dessa poderosa ferramenta na área. / The computer is playing an increasing role in the life of the modern man. With this point of view the design and more specifically the building design can make the computer a valuable tool. However, despite the potential of this equipment, it has not been yet properly used. This happens because the designers do not know the actual possibilities of the use of computers for the building designs. This Dissertation aims to organize the concepts related with this possibilities and also to bring out the prospective uses of this power full tool in this area.

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