1 resultado para digital tools
em AMS Tesi di Laurea - Alm@DL - Università di Bologna
Filtro por publicador
- JISC Information Environment Repository (4)
- Repository Napier (1)
- ABACUS. Repositorio de Producción Científica - Universidad Europea (1)
- Abertay Research Collections - Abertay University’s repository (1)
- Academic Archive On-line (Stockholm University; Sweden) (1)
- Acceda, el repositorio institucional de la Universidad de Las Palmas de Gran Canaria. España (1)
- Adam Mickiewicz University Repository (1)
- AMS Tesi di Dottorato - Alm@DL - Università di Bologna (4)
- AMS Tesi di Laurea - Alm@DL - Università di Bologna (1)
- Aquatic Commons (1)
- Aston University Research Archive (4)
- B-Digital - Universidade Fernando Pessoa - Portugal (2)
- Biblioteca Digital - Universidad Icesi - Colombia (1)
- Biblioteca Digital | Sistema Integrado de Documentación | UNCuyo - UNCUYO. UNIVERSIDAD NACIONAL DE CUYO. (1)
- Biblioteca Digital da Câmara dos Deputados (1)
- Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (2)
- Biblioteca Digital de Teses e Dissertações Eletrônicas da UERJ (3)
- BORIS: Bern Open Repository and Information System - Berna - Suiça (13)
- Brock University, Canada (3)
- Bucknell University Digital Commons - Pensilvania - USA (4)
- Bulgarian Digital Mathematics Library at IMI-BAS (7)
- Cambridge University Engineering Department Publications Database (2)
- CentAUR: Central Archive University of Reading - UK (10)
- Center for Jewish History Digital Collections (1)
- Cochin University of Science & Technology (CUSAT), India (2)
- Comissão Econômica para a América Latina e o Caribe (CEPAL) (5)
- CORA - Cork Open Research Archive - University College Cork - Ireland (2)
- Cornell: DigitalCommons@ILR (1)
- Dalarna University College Electronic Archive (2)
- Deakin Research Online - Australia (25)
- Digital Commons - Michigan Tech (5)
- Digital Commons @ Center for the Blue Economy - Middlebury Institute of International Studies at Monterey (1)
- Digital Commons @ DU | University of Denver Research (1)
- Digital Commons at Florida International University (12)
- Digital Peer Publishing (2)
- DigitalCommons - The University of Maine Research (1)
- Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland (1)
- DRUM (Digital Repository at the University of Maryland) (3)
- eResearch Archive - Queensland Department of Agriculture; Fisheries and Forestry (6)
- Glasgow Theses Service (2)
- Helda - Digital Repository of University of Helsinki (3)
- Indian Institute of Science - Bangalore - Índia (12)
- Instituto Politécnico de Bragança (1)
- Instituto Politécnico de Castelo Branco - Portugal (1)
- Instituto Politécnico de Viseu (1)
- Instituto Politécnico do Porto, Portugal (6)
- Instituto Superior de Psicologia Aplicada - Lisboa (1)
- Massachusetts Institute of Technology (1)
- Memorial University Research Repository (1)
- Ministerio de Cultura, Spain (1)
- Nottingham eTheses (1)
- Plymouth Marine Science Electronic Archive (PlyMSEA) (1)
- Portal de Revistas Científicas Complutenses - Espanha (3)
- QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast (6)
- Queensland University of Technology - ePrints Archive (633)
- RCAAP - Repositório Científico de Acesso Aberto de Portugal (1)
- RDBU - Repositório Digital da Biblioteca da Unisinos (1)
- Repositório Aberto da Universidade Aberta de Portugal (1)
- Repositório Alice (Acesso Livre à Informação Científica da Embrapa / Repository Open Access to Scientific Information from Embrapa) (1)
- Repositório Científico do Instituto Politécnico de Lisboa - Portugal (3)
- Repositorio de la Universidad de Cuenca (2)
- Repositório digital da Fundação Getúlio Vargas - FGV (1)
- Repositorio Institucional da UFLA (RIUFLA) (1)
- Repositório Institucional da Universidade de Aveiro - Portugal (3)
- Repositório Institucional da Universidade de Brasília (1)
- Repositório Institucional da Universidade Estadual de São Paulo - UNESP (1)
- Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho" (40)
- RUN (Repositório da Universidade Nova de Lisboa) - FCT (Faculdade de Cienecias e Technologia), Universidade Nova de Lisboa (UNL), Portugal (3)
- Savoirs UdeS : plateforme de diffusion de la production intellectuelle de l’Université de Sherbrooke - Canada (1)
- Universidad de Alicante (3)
- Universidad del Rosario, Colombia (6)
- Universidad Politécnica de Madrid (13)
- Universidade de Lisboa - Repositório Aberto (2)
- Universidade Federal do Pará (2)
- Universidade Federal do Rio Grande do Norte (UFRN) (4)
- Universidade Metodista de São Paulo (4)
- Universita di Parma (2)
- Universitat de Girona, Spain (2)
- Universitätsbibliothek Kassel, Universität Kassel, Germany (2)
- Université de Montréal, Canada (2)
- Université Laval Mémoires et thèses électroniques (1)
- University of Connecticut - USA (2)
- University of Michigan (12)
- University of Queensland eSpace - Australia (1)
- University of Southampton, United Kingdom (3)
- University of Washington (2)
- Worcester Research and Publications - Worcester Research and Publications - UK (1)
Resumo:
In this work we study a model for the breast image reconstruction in Digital Tomosynthesis, that is a non-invasive and non-destructive method for the three-dimensional visualization of the inner structures of an object, in which the data acquisition includes measuring a limited number of low-dose two-dimensional projections of an object by moving a detector and an X-ray tube around the object within a limited angular range. The problem of reconstructing 3D images from the projections provided in the Digital Tomosynthesis is an ill-posed inverse problem, that leads to a minimization problem with an object function that contains a data fitting term and a regularization term. The contribution of this thesis is to use the techniques of the compressed sensing, in particular replacing the standard least squares problem of data fitting with the problem of minimizing the 1-norm of the residuals, and using as regularization term the Total Variation (TV). We tested two different algorithms: a new alternating minimization algorithm (ADM), and a version of the more standard scaled projected gradient algorithm (SGP) that involves the 1-norm. We perform some experiments and analyse the performance of the two methods comparing relative errors, iterations number, times and the qualities of the reconstructed images. In conclusion we noticed that the use of the 1-norm and the Total Variation are valid tools in the formulation of the minimization problem for the image reconstruction resulting from Digital Tomosynthesis and the new algorithm ADM has reached a relative error comparable to a version of the classic algorithm SGP and proved best in speed and in the early appearance of the structures representing the masses.