I.F. Aymerich

Publications of I.F. Aymerich

• Planning the installation of the European Multidisciplinary Sea-floor Observatory (EMSO): First approach using geographic information systems (GIS)

  Authors: I.F. Aymerich, J. Piera, J.J. Danobeitia

  OCEANS, 2011 IEEE - Spain; 07/2011

  The design, installation and maintenance of any submarine cable are difficult tasks necessary done for long-term submarine observatories. Cable installation and maintenance is one of the mostThe design, installation and maintenance of any submarine cable are difficult tasks necessary done for long-term submarine observatories. Cable installation and maintenance is one of the most expensive parts of a submarine cable system. To reduce costs, computer-based approaches are used for planning the installation and the maintenance of these networks. This contribution wants to briefly describe some basis to take into account in the framework of the European Multidisciplinary Sea-floor Observatory (EMSO). Quality improvements can reduce costs in cable installations. Submarine cable installation quantity is dramatically increasing, and these new tools minimize human error and reduce the added time at sea due to errors, reducing costs at the same time.

• Potential support vector machines and Self-Organizing Maps for phytoplankton discrimination

  Authors: I.F. Aymerich, J. Piera, A. Soria-Frisch

  Neural Networks (IJCNN), The 2010 International Joint Conference on; 08/2010

  Fluorescence spectroscopy is a powerful technique usually used to evaluate phytoplankton marine environments. In this study, a kernel method (Potential Support Vector Machine, P-SVM) is presented,Fluorescence spectroscopy is a powerful technique usually used to evaluate phytoplankton marine environments. In this study, a kernel method (Potential Support Vector Machine, P-SVM) is presented, evaluating its capability to achieve phytoplankton classification from its fluorescence spectra. Different phytoplankton species were studied, and their fluorescence spectra were acquired in laboratory. In a previous study working with Self-Organizing Maps (SOM), it was proved with experimental data from laboratory that excitation spectra were more discriminative than emission spectra. It was also shown that using some preprocessing techniques, such as derivative analysis, the classification performance from emission fluorescence data can be improved. The classification results were encouraging to keep working with emission fluorescence, and herein we present a comparison between P-SVM and SOM for this goal.

• Fast phytoplankton classification from fluorescence spectra: comparison between PSVM and SOM

  Authors: I.F. Aymerich, J. Piera, J. Mohr, A. Soria-Frisch, K. Obermayer

  OCEANS 2009 - EUROPE; 06/2009

  Evaluation of phytoplankton communities is an important task to characterize marine environments. Fluorescence spectroscopy is a powerful technique usually used for this goal. This study presents aEvaluation of phytoplankton communities is an important task to characterize marine environments. Fluorescence spectroscopy is a powerful technique usually used for this goal. This study presents a comparison between two different techniques for fast phytoplankton discrimination: Self-Organizing Maps (SOM) and Potential Support Vector Machines (P-SVM), evaluating its capability to achieve phytoplankton classification from its fluorescence spectra. Several cultures representing different algae groups were grown under the same conditions and their emission fluorescence spectra were measured every day. Finally, the classification results obtained from both techniques, SOM and P-SVM, are presented. In the case of using emission fluorescence spectra, the results show that we are able to reduce the acquisition time required for some of the existing techniques, obtaining encouraging classification performance.

• Effect of spectral resolution in hyperspectral data analysis

  Authors: E. Torrecilla, I.F. Aymerich, S. Pons, J. Piera

  Geoscience and Remote Sensing Symposium, 2007. IGARSS 2007. IEEE International; 08/2007

  The effect of hyperspectral data resolution on the results obtained using derivative spectroscopy is discussed in this article. A comparison was made between attenuation spectra measured using twoThe effect of hyperspectral data resolution on the results obtained using derivative spectroscopy is discussed in this article. A comparison was made between attenuation spectra measured using two different hyperspectral sensors with 3648 and 256 spectral bands, respectively. Smoothing and derivative algorithms were applied to both types of spectral data in order to assess qualitative information from the spectral features of several laboratory samples. In order to make an optimal application of the derivative analysis, a suitable selection of the smoothing and derivating parameters was done according to the resolution of each type of hyperspectral data. Second derivative spectra were obtained and peaks related to the absorption bands of pigments present in the considered samples were identified in both cases. Furthermore, interpolation techniques were applied so as to match spectral resolutions of data collected by the two sensors and negligible variations in the positions of the peaks were achieved in the derivative spectra.

• Monolithic spectrometer for environmental monitoring applications

  Authors: S. Pons, I.F. Aymerich, E. Torrecilla, J. Piera

  OCEANS 2007 - Europe; 07/2007

  Hyperspectral data analysis has been shown to be a reliable technique to identify several water components. Currently, there are numerous commercially available miniature spectrometer systems as wellHyperspectral data analysis has been shown to be a reliable technique to identify several water components. Currently, there are numerous commercially available miniature spectrometer systems as well as discrete components that are used by researchers in designing their own systems. We have developed a custom-designed hyperspectral sensor. Experimental results and potential applications are discussed on this article. It can be used as a low cost optical monitoring system to be employed on fish farming and aquaculture facilities.

• Effect of spectral resolution in hyperspectral data analysis

  Authors: E. Torrecilla, I.F. Aymerich, S. Pons, J. Piera

  01/2007

  The effect of hyperspectral data resolution on the results obtained using derivative spectroscopy is discussed in this article. A comparison was made between attenuation spectra measured using twoThe effect of hyperspectral data resolution on the results obtained using derivative spectroscopy is discussed in this article. A comparison was made between attenuation spectra measured using two different hyperspectral sensors with 3648 and 256 spectral bands, respectively. Smoothing and derivative algorithms were applied to both types of spectral data in order to assess qualitative information from the spectral features of several laboratory samples. In order to make an optimal application of the derivative analysis, a suitable selection of the smoothing and derivating parameters was done according to the resolution of each type of hyperspectral data. Second derivative spectra were obtained and peaks related to the absorption bands of pigments present in the considered samples were identified in both cases. Furthermore, interpolation techniques were applied so as to match spectral resolutions of data collected by the two sensors and negligible variations in the positions of the peaks were achieved i

• Comparative response of two different hyperspectral sensors. Application to derivative analysis of absorption spectra

  Authors: E. Torrecilla, S. Pons, I.F. Aymerich, J. Piera

  Instrumentation ViewPoint. 01/2007; 6:86--87.

• Low cost hyperspectral device suitable for monitoring sensor networks

  Authors: S. Pons, I.F. Aymerich, E. Torrecilla, J. Piera

  Instrumentation ViewPoint. 01/2007; 6:60--61.