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Author Rodriguez-Alvarez, M.J.; Sanchez, F.; Soriano, A.; Iborra, A.; Mora, C.
Title Exploiting symmetries for weight matrix design in CT imaging Type Journal Article
Year 2011 Publication Mathematical and Computer Modelling Abbreviated Journal Math. Comput. Model.
Volume 54 Issue 7-8 Pages 1655-1664
Keywords Computerized tomography imaging; Polar grid; System matrix; Rotation symmetries; ART
Abstract In this paper we propose several methods of constructing the system matrix (SM) of a Computed Tomography (CT) scanner with two objectives: (1) to construct SMs in the shortest possible time and store them in an ordinary PC without losing quality, (2) to analyze the possible applications of the proposed method to 3D, taking into account SMs' sizes, computing time and reconstructed image quality. In order to build the SM, we propose two new field of view (FOV) pixellation schemes, based on a polar coordinate system (polar grid) by taking advantage of the polar rotation symmetries of CT devices. Comparisons between the SMs proposed are performed using two phantom and a real CT-simulator images. Global error, contrast, noise and homogeneity of the reconstructed images are discussed.
Address [Rodriguez-Alvarez, MJ; Iborra, A; Mora, C] Univ Politecn Valencia, Inst Matemat Multidisciplinar, Valencia 46022, Spain, Email: mjrodri@imm.upv.es
Corporate Author Thesis
Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0895-7177 ISBN Medium
Area Expedition Conference
Notes WOS:000293269200007 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 708
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Author Mendez, V.; Amoros, G.; Kaci, M.
Title A Decentralized Deployment Strategy and Performance Evaluation of LCG File Catalog Service Type Journal Article
Year 2011 Publication Journal of Grid Computing Abbreviated Journal J. Grid Comput.
Volume 9 Issue 3 Pages 345-354
Keywords Distributed computing; Grid computing; Performance; Catalog
Abstract The LHC Computing Grid (LCG) leads by CERN, has solved with the LCG File Catalog (LFC) the major problem of scaling the data management catalog. However, additional performance issues should be faced to deploy a painless catalog service. With this aim, we present a decentralized LFC server configuration, and its performance evaluation compared with the traditional LFC deployment. A performance analysis is shown, including not only the catalog server, but also analysing the client side overhead. We find that the LFC service has in the clients a relevant workload of the overall service. The experimental results show that the proposed LFC deployment for servers and clients, improves the performance of the service.
Address [Munoz, VM; Vicente, GA; Kaci, M] CSIC, Mixed Inst, Inst Fis Corpuscular IFIC, Grid & E Sci Grp, Valencia 46071, Spain, Email: vmendez@ific.uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 1570-7873 ISBN Medium
Area Expedition Conference
Notes WOS:000293973700004 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 721
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Author Tain, J.L. et al; Algora, A.; Estevez, E.; Rubio, B.; Valencia, E.; Jordan, D.
Title Beta Decay Studies of Neutron Rich Nuclei Using Total Absorption Gamma-ray Spectroscopy and Delayed Neutron Measurements Type Journal Article
Year 2011 Publication Journal of the Korean Physical Society Abbreviated Journal J. Korean Phys. Soc.
Volume 59 Issue 2 Pages 1499-1502
Keywords Beta decay; Delayed neutron emission; Total absorption gamma-ray spectroscopy; Neutron detectors; Nuclear technology; Nuclear astrophysics
Abstract A complete characterisation of the beta-decay of neutron-rich nuclei can be obtained from the measurement of beta-delayed gamma rays and, whenever the process is energetically possible, beta-delayed neutrons. The accurate determination of the beta-intensity distribution and the beta-delayed neutron emission probability is of great relevance in the fields of reactor technology and nuclear astrophysics. A programme for combined measurements using the total absorption gamma-ray spectroscopy technique and both neutron counters and neutron time-of-flight spectrometers is presented.
Address [Tain, JL; Algora, A; Estevez, E; Rubio, B; Valencia, E; Jordan, D] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia 46071, Spain, Email: tain@ific.uv.es
Corporate Author Thesis
Publisher Korean Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0374-4884 ISBN Medium
Area Expedition Conference
Notes WOS:000294080700010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 730
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Author n_TOF Collaboration (Guerrero, C. et al); Domingo-Pardo, C.; Tain, J.L.
Title Study of Photon Strength Function of Actinides: the Case of (235)U, (238)Np and (241)Pu Type Journal Article
Year 2011 Publication Journal of the Korean Physical Society Abbreviated Journal J. Korean Phys. Soc.
Volume 59 Issue 2 Pages 1510-1513
Keywords Photon/Gamma strength functions; Pygmy; Scissor mode; n_TOF; Total absorption calorimeter; TAC; Neutron capture
Abstract The decay from excited levels in medium and heavy nuclei can be described in a statistical approach by means of Photon Strength Functions and Level Density distributions. The study of electromagnetic cascades following neutron capture based on the use of high efficiency detectors has been shown to be well suited for probing the properties of the Photon Strength Function of heavy (high level density) and/or radioactive (high background) nuclei. In this work we have investigated for the first time the validity of the recommended PSF of actinides, in particular (235)U, (238)Np and (241)Pu. Our study includes the search for resonance structures in the PSF below S(n) and draws conclusions regarding their existence and their characteristics in terms of energy, width and electromagnetic nature.
Address [Guerrero, C; Alvarez-Velarde, F; Ano-Ott, DC; Martinez, T; Mendoza, E; Villamarin, D] Ctr Invest Energet Medioambientales & Technol CIE, Madrid, Spain, Email: carlos.guerrero@ciemat.es
Corporate Author Thesis
Publisher Korean Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0374-4884 ISBN Medium
Area Expedition Conference
Notes WOS:000294080700013 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 731
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Author Pino, F.; Roe, N.; Orero, A.; Falcon, C.; Rojas, S.; Benlloch, J.M.; Ros, D.; Pavia, J.
Title Development of a variable-radius pinhole SPECT system with a portable gamma camera Type Journal Article
Year 2011 Publication Revista Española de Medicina Nuclear Abbreviated Journal Rev. Esp. Med. Nucl.
Volume 30 Issue 5 Pages 286-291
Keywords SPECT; Small animal; Pinhole; Portable gamma camera; Continuous scintillator
Abstract Objective: To develop a small-animal SPECT system using a low cost commercial portable gamma camera equipped with a pinhole collimator, a continuous scintillation crystal and a position-sensitive photomultiplier tube. Material and methods: The gamma camera was attached to a variable radius system, which enabled us to optimize sensitivity and resolution by adjusting the radius of rotation to the size of the object. To investigate the capability of the SPECT system for small animal imaging, the dependence of resolution and calibration parameters on radius was assessed and acquisitions of small phantoms and mice were carried out. Results: Resolution values, ranging from 1.0 mm for a radius of 21.4 mm and 1.4 mm for a radius of 37.2 mm were obtained, thereby justifying the interest of a variable radius SPECT system. Conclusions: The image quality of phantoms and animals were satisfactory, thus confirming the usefulness of the system for small animal SPECT imaging.
Address [Pino, F; Roe, N; Ros, D] Univ Barcelona, Fac Med, Unitat Biofis, Barcelona 7, Spain, Email: fpino@iconcologia.net
Corporate Author Thesis
Publisher Elsevier Science Inc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0212-6982 ISBN Medium
Area Expedition Conference
Notes WOS:000294659400004 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 753
Permanent link to this record