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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.
21

Sensibilidade e especificidade dos métodos de diagnóstico por imagem (ultrassonografia, ressonância magnética e tomografia computadorizada) na detecção de nódulos hepáticos no cirrótico com correlação histológica do explante / Sensitivity and specificity of imaging diagnostic methods (ultrasonography, magnetic resonanceand computed tomography) in the detection of liver nodules in cirrhotic patients, with histological correlation of the explanted liver

Fausto, Carmen Silvia Cerqueira do Val 13 December 2011 (has links)
INTRODUÇÃO: Os equipamentos dos métodos diagnósticos por imagem estão em constante e rápido desenvolvimento tecnológico, o que tem levado ao aprimoramento da detecção dos nódulos de carcinoma hepatocelular em pacientes cirróticos. OBJETIVO: Comparar prospectivamente a sensibilidade e a especificidade dos diferentes métodos diagnósticos de imagem na detecção de nódulos hepáticos em pacientes cirróticos com os explantes hepáticos. MÉTODOS: Vinte pacientes aguardando transplante hepático foram avaliados pela ultrassonografia (por dois examinadores independentes: US1 e US2), pela ressonância magnética (RM) e pela tomografia computadorizada (TC). Os resultados foram comparados com os explantes hepáticos para avaliar os nódulos quanto à localização e ao diâmetro e foram classificados como macronódulo regenerativo, nódulo displásico, carcinoma hepatocelular, hemangioma e hepatocolangiocarcinoma. A sensibilidade e a especificidade foram calculadas através de tabelas 2 x 2 e o teorema de Bayes. O nível de significância adotado foi de 5% ( = 0,05). RESULTADOS: O exame anatomopatológico classificou 50 nódulos: 27(54%) como macronódulo regenerativo, 12(24%) como carcinoma hepatocelular, 9(18%) como nódulos displásicos, 1(2,0%) como hemangioma e 1(2,0%) como hepatocolangiocarcinoma. A sensibilidade e a especificidade para detecção de nódulos em geral foram 20%(10/50) e 95% para US1; 18%(9/50) e 98% para US2; 24%(12/50) e 96% para RM; 18%(09/50) e 96% para TC, respectivamente. A sensibilidade e a especificidade para a detecção de carcinoma hepatocelular foram 42%(05/12) e 87% para US1; 42%(05/12) e 89% para US2; 58%(07/12) e 87% para RM e 50%(06/12) e 92% para TC, respectivamente. CONCLUSÃO: Os métodos diagnósticos por imagem avaliados apresentaram sensibilidade e especificidade semelhantes para detecção de nódulos no fígado cirrótico / INTRODUCTION: Imaging diagnostic methods undergo constant and fast technological development, which has led to the improvement in the detection of hepatocellular carcinoma nodules in cirrhotic patients. OBJECTIVE: To prospectively compare the sensitivity and specificity of different imaging diagnostic methods in the detection of liver nodules in cirrhotic patients with the explanted liver. METHODS: Twenty patients awaiting liver transplant were assessed by ultrasonography (by two independent examiners: US1 and US2), magnetic resonance (MR) and multislice computed tomography (CT). The results were compared to the explanted livers to evaluate location and diameter of the nodules, which were classified as regenerative macronodule, dysplastic nodule, hepatocellular carcinoma, hemangioma and hepatocholangiocarcinoma. Sensitivity and Specificity were calculated through 2 x 2 Tables with Bayes Theorem. The level of significance was set at 5% ( = 0.05). RESULTS: The anatomopathological assessment classified 50 nodules: 27 (54%) as macroregenerative, 12 (24%) as hepatocellular carcinoma, 9 (18%) as dysplastic nodules, 1 (2%) as hemangioma and 1 (2%) as hepatocholangiocarcinoma. Sensitivity and specificity for general nodule detection were 20% (10/50) and 95% for US1, 18% (9/50) and 98% for US2, 24% (12/50) and 96% for MR and 18%(09/50) and 96% for CT, respectively. Sensitivity and specificity for hepatocellular carcinoma detection was 42% (5/12) and 87% for US1; 42% (5/12) and 89% for US2; 58% (7/12) and 87% for MR and 50% (6/12) and 92% for CT, respectively. CONCLUSION: The imaging diagnostic methods evaluated in the study showed similar sensitivity and specificity for nodule detection in the cirrhotic liver
22

Development of a Framework for Concept Selection and Design Automation : Utilizing hybrid modeling for indirect parametric control of subdivision surfaces

Eklund, Adam, Karner, Jesper January 2017 (has links)
Saab Aeronautics’ section Overall Design and Survivability develops early aircraft concepts and utilizes Computer Aided Design (CAD) to ensure the feasibility of principal- and critical characteristics. Saab has over the years developed several start models of aircrafts in CAD from pre-defined aircraft configurations, which are to some extent non-generic. When new configurations are to be explored, manual- and repetitive work is required if the new configuration cannot be attained solely through parametric modifications of a start model. The complexity of these CAD models also demands great knowledge of how aircraft components interact with each other to ensure compatibility. The project covered in this thesis was thus carried out to develop a more effective way for Saab to create and explore a larger design space. This by creating a framework that consists of a product configurator coupled with a library of generic CAD models. The product configurator that was created is the Saab Tradespace Analyzer & Reconfigurator (STAR), which takes compatibility relationships into consideration to facilitate concept selection. The STAR also provides a dynamic design space calculation to indicate how close the user is to a final concept selection. Two generic CAD models were created, a fuselage model and an air inlet model. A skeleton model was also created in order to reduce model dependencies and to control the main geometry of the aircraft product. In addition to these, an already existing wing model was implemented to form the library of generic CAD models. The framework coupling the STAR with the CAD library utilizes design automation to allow automatic CAD model generation of a concept that has been selected within the STAR. It was concluded through extrapolation that the created framework would allow Saab to create and explore a larger design space in a more effective way than what is done today, provided the library of CAD models were to contain the same number of components as today’s start models.
23

Design Automation of Air Intake Lips on an Aircraft : How to implement design automation for air intake lips in a later design concept phase

Blixt, Wilma, Schönning, Hilda January 2023 (has links)
Air intakes are complex components that are critical for the propulsion of the aircraft. The design has to consider requirements from several different departments, often contradictory. Additionally, the air intakes need to cooperate with other critical components. This makes testing of the models crucial, hence time-demanding. Design automation is a growing field which aims at minimizing repetitive work during product concept development. To follow the increasing digitalization, further investigations of design automation applied on air intakes are significant.  The application Imagine and Shape in 3D Experience CATIA handles subdivided surfaces. These surfaces are both flexible and provide a high order of continuity, which is often desired. While design automation in CATIA is well investigated, design automation in Imagine and Shape is not.  Knowledge based engineering techniques are often used to implement design automation. The methodology MOKA is frequently used when developing knowledge based engineering applications. This master thesis has followed MOKA in combination with Scrum.  The master thesis has resulted in a method to allow automation in Imagine and Shape by linking mesh nodes on subdivided surfaces to reference points that are parameterized. Further, a method for generating air intake configurations as well as the integration with a fuselage has been developed. The method includes wireframe models in Generative Shape Design, subdivided surfaces in Imagine and Shape, scripts in EKL as well as UserForm and scripts in VBA. Additionally, the order of continuity for an integration between air intakes and fuselage has been analyzed using tools in 3D Experience CATIA.  A conclusion drawn is that the method for generating air intakes cannot be completely automated. Instantiation and dimension of components can be automated, but manual work is required when using tools in Imagine and Shape during the integration between the components and the fuselage.Two methods for linking mesh nodes to reference points have been identified, one manual and one semi-automatic. The automatic method saves time and mouse clicks by utilizing VBA scripts. Further, the achieved order of continuity of an integration between subdivided surfaces depends on the individual components.
24

Le discours sur la ville dans les films d'anticipation

Cloutier, Caroline 25 April 2018 (has links)
Ce mémoire a pour objet d'étude la ville et l'architecture dans les films d'anticipation. Le cinéma y est pris dans sa dimension critique, c'est-à-dire dans sa capacité de formuler des discours sur la ville et l'architecture. Ces discours se comprennent par la mise en relief des conditions d'émergence des films et par extension, celle de leurs décors. L'idée que l'on se fait de la ville du futur dépend donc de facteurs contemporains à chaque film : le contexte socio-politique, économique et culturel dans lequel un film a été produit, les théories et pratiques de l'architecture à la même époque ainsi que l'histoire que raconte le film sont quelques-uns de ces facteurs. Cette étude présente donc l'analyse de quelques films d'anticipation sélectionnés à travers toute l'histoire du cinéma. Metropolis de Fritz Lang, Just Imagine de David Butler, Alphaville de Jean-Luc Godard, la trilogie Star Wars de George Lucas et Blade Runner de Ridley Scott sont les sujets principaux de ce mémoire. / Québec Université Laval, Bibliothèque 2014
25

An assessment of the impacts of land use changes on the Duthuni wetland stream using remote sensing, GIS and social surveying: a case study in Limpopo Province, South Africa

Nephawe, Mbavhalelo 18 September 2017 (has links)
MENVSC / Department of Geography and Geo-Information Sciences / This is a case study research that focuses on the assessment of the impacts of land use changes on the Duthuni wetland ecosystem in Limpopo Province using geospatial techniques and Social Survey. SPOT 4 satellite images which covered the time frame between 1999, 2005 to 2012, were used. The unit of analysis included different institutions such as the local municipality, farmers, the heads of the households and Chief of the Village. In this study, different methods of sampling were used in different context for selecting participants and for sample size determination. The different instruments for data collection included the questionnaires, interviews, focus group interviews and documents review. Socio-economic survey and review of documents were carried out to understand historical trends, collect ground truth and other secondary information required. Data collected from the survey were captured and analysed using the Statistical Package for Scientific Solutions (SPSS). For quantitative analysis, Chi-Square and cross tabulation were employed in SPSS. Analysis of satellite imagery was accomplished through integrated use of ERDAS Imagine (version 2015) and ArcGIS (version 10.1) software package. The themes were identified and analysed using the content analysis based on the main research topics. The results show that the land use/ cover changes have occurred at an unprecedented rate over the years 1999 to 2012. From the year 1999 to the year 2012, the total land use/ cover conversions equal to 299.984 ha of land. The trend and spatial extent of land use/ cover changes had undergone considerable changes over the years in the study period. The major contributing factors included population increase, expansion of agriculture and lack of space to settle. The residential area was found to be the major factor contributing to land use change over the years with an increase of (102.87ha.). People residing in Duthuni village especially along the wetland ecosystem consist of the majority of female-headed households. There is no proper facilitation and mentoring in the village by the government in order to resolve social problems when it comes to land use change. Water pollution and soil erosion were found to be the major concern by wetland users such as farmers and residents. Lack of knowledge has also been identified as one of the driving factors of environmental impacts of land use change in the area. Food was the most resources with 41% which the community gets from the wetland.

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