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Tendela L.P.,Institute Fisica Rosario | Galizzi G.E.,Institute Fisica Rosario | Federico A.,Instituto Nacional Of Tecnologia Industrial | Kaufmann G.H.,Institute Fisica Rosario | Kaufmann G.H.,Centro Internacional Franco Argentino Of Ciencias Of La Informacion Y Of Sistemas
Optics and Lasers in Engineering | Year: 2015

Recently, a phase evaluation method was proposed to measure nanometric displacements by means of digital speckle pattern interferometry when the phase change introduced by the deformation is in the range [0,π) rad. This method is based on the evaluation of a correlation coefficient between two speckle interferograms generated by both deformation states of the object. In this paper, we present a novel technique to measure non-monotonous displacements in temporal speckle pattern interferometry using a correlation method without a temporal carrier. In this approach, the sign ambiguity is resolved automatically due to the introduction of a function that determines the correct sign of the displacement between two consecutive speckle interferograms. The rms phase errors introduced by the proposed method are determined using computer-simulated speckle interferograms. An application of the phase retrieval method to process experimental data is also presented. © 2015 Elsevier Ltd. All rights reserved.


Casali A.,National University of Rosario | Casali A.,Centro Internacional Franco Argentino Of Ciencias Of La Informacion Y Of Sistemas | Deco C.,National University of Rosario | Deco C.,University Catolica Argentina Sede Rosario | Beltramone S.,National University of Rosario
Revista Iberoamericana de Tecnologias del Aprendizaje | Year: 2016

This paper presents an assistant to populate institutional repositories. This tool can detect all educational digital objects in a text format that are already published on institutional Websites and can be uploaded to a repository. This recopilation is a tedious task and is usually performed manually. In this paper, we propose a system architecture for automating this task of collecting text documents within a restricted domain in order to detect plausible documents that can be loaded into a repository. In addition, its metadata, such as language, category, title, authors, and their contact data, is automatically extracted. A prototype of this system was developed, and case studies in two different domains are analyzed. © 2013 IEEE.


Bernini M.B.,Institute Fisica Rosario | Federico A.,Instituto Nacional Of Tecnologia Industrial | Kaufmann G.H.,Institute Fisica Rosario | Kaufmann G.H.,Centro Internacional Franco Argentino Of Ciencias Of La Informacion Y Of Sistemas
Applied Optics | Year: 2011

We propose a phase measurement technique to retrieve optical phase distributions coded in noisy temporal speckle pattern interferometry signals presenting regions of adjacent low-modulated pixels, which is based on the bidimensional empirical mode decomposition and the Hilbert transform. It is shown that this approach can effectively remove noise and minimize the influence of large sets of adjacent nonmodulated pixels located in the time series of speckle interferograms. The performance of the phase retrieval approach is analyzed using computer-simulated speckle interferograms modulated with a temporal carrier. The results are also compared with those given by a technique based on the one-dimensional empirical mode decomposition. The advantages and limitations of the proposed approach are finally discussed. © 2011 Optical Society of America.


Tendela L.P.,Institute Fisica Rosario | Galizzi G.E.,Institute Fisica Rosario | Federico A.,Instituto Nacional Of Tecnologia Industrial | Kaufmann G.H.,Institute Fisica Rosario | Kaufmann G.H.,Centro Internacional Franco Argentino Of Ciencias Of La Informacion Y Of Sistemas
Applied Optics | Year: 2011

This paper presents a method to measure nanometric displacement fields using digital speckle pattern interferometry, which can be applied when the generated correlation fringes show less than one complete fringe. The method is based on the evaluation of the correlation between the two speckle interferograms generated by both deformation states of the object. The performance of the proposed method is analyzed using computer-simulated speckle interferograms. A comparison with the performance given by a phaseshifting technique is also presented, and the advantages and limitations of the proposed method are discussed. Finally, the performance of the proposedmethod to process real data is illustrated. ©2011 Optical Society of America.


Tendela L.P.,Institute Fisica Rosario | Galizzi G.E.,Institute Fisica Rosario | Federico A.,Instituto Nacional Of Tecnologia Industrial | Kaufmann G.H.,Institute Fisica Rosario | Kaufmann G.H.,Centro Internacional Franco Argentino Of Ciencias Of La Informacion Y Of Sistemas
Optics and Lasers in Engineering | Year: 2012

A phase evaluation method was recently proposed to measure nanometric displacements by means of digital speckle pattern interferometry when the phase change introduced by the deformation is in the range [0,π)rad. To evaluate the phase change, however, it is necessary to record separately the intensities of the object and the reference beams corresponding to both the initial and the deformed interferograms. This paper presents a fast approach that overcomes this limitation. The rms phase errors introduced by the proposed method are determined using computer-simulated speckle interferograms and its performance is also compared with the results obtained with a phase-shifting technique. An application of the proposed phase retrieval method to process experimental data is finally illustrated. © 2011 Elsevier Ltd. All rights reserved.

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