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Rome, Italy

Calderisi M.,University of Modena and Reggio Emilia | Calderisi M.,Consortium for Science and Technology of Materials | Ulrici A.,University of Modena and Reggio Emilia | Ulrici A.,Consortium for Science and Technology of Materials | And 5 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

The EU FP7 project CUSTOM (Drugs and Precursor Sensing by Complementing Low Cost Multiple Techniques) aims at developing a new sensing system for the detection of drug precursors in gaseous samples, which includes an External Cavity-Quantum Cascade Laser Photo-Acoustic Sensor (EC-QCLPAS) that is in the final step of realisation. Thus, a simulation based on FT-IR literature spectra has been accomplished, where the development of a proper strategy for the design of the composition of the environment, as much as possible realistic and representative of different scenarios, is of key importance. To this aim, an approach based on the combination of signal processing and experimental design techniques has been developed. The gaseous mixtures were built by adding the considered 4 drug precursor (target) species to the gases typically found in atmosphere, taking also into account possible interfering species. These last chemicals were selected considering custom environments (20 interfering chemical species), whose concentrations have been inferred from literature data. The spectra were first denoised by means of a Fast Wavelet Transform-based algorithm; then, a procedure based on a sigmoidal transfer function was developed to multiply the pure components spectra by the respective concentration values, in a way to correctly preserve background intensity and shape, and to operate only on the absorption bands. The noise structure of the EC-QCLPAS was studied using sample spectra measured with a prototype instrument, and added to the simulated mixtures. Finally a matrix containing 5000 simulated spectra of gaseous mixtures was built up. © 2012 SPIE. Source


Ulrici A.,University of Modena and Reggio Emilia | Ulrici A.,Consortium for Science and Technology of Materials | Seeber R.,Consortium for Science and Technology of Materials | Seeber R.,University of Modena and Reggio Emilia | And 6 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

In the frame of the EU project CUSTOM, a new sensor system for the detection of drug precursors in gaseous samples is being developed, which also includes an External Cavity-Quantum Cascade Laser Photo Acoustic Sensor (ECQCLPAS). In order to define the characteristics of the laser source, the optimal wavenumbers within the most effective 200 cm -1 range in the mid-infrared region must be identified, in order to lead to optimal detection of the drug precursor molecules in presence of interfering species and of variable composition of the surrounding atmosphere. To this aim, based on simulations made with FT-IR spectra taken from literature, a complex multivariate analysis strategy has been developed to select the optimal wavenumbers. Firstly, the synergistic use of Experimental Design and of Signal Processing techniques led to a dataset of 5000 simulated spectra of mixtures of 33 different gases (including the 4 target molecules). After a preselection, devoted to disregard noisy regions due to small interfering molecules, the simulated mixtures were then used to select the optimal wavenumber range, by maximizing the classification efficiency, as estimated by Partial Least Squares - Discriminant Analysis. A moving window 200 cm -1 wide was used for this purpose. Finally, the optimal wavenumber values were identified within the selected range, using a feature selection approach based on Genetic Algorithms and on resampling. The work made will be relatively easily turned to the spectra actually recorded with the newly developed EC-QCLPAS instrument. Furthermore, the proposed approach allows progressive adaptation of the spectral dataset to real situations, even accounting for specific, different environments. © 2012 SPIE. Source


Zhurbenko V.,Technical University of Denmark | Krozer V.,Goethe University Frankfurt | Kotiranta M.,Goethe University Frankfurt | Bouamrane F.,Thales Alenia | And 4 more authors.
Proceedings of the 5th European Conference on Antennas and Propagation, EUCAP 2011 | Year: 2011

In spite of the fact that the technology is constantly advancing, the realization of terahertz components is still heavily constrained by problems arising from technological limitations. As a result, the design of terahertz components still remains a challenging problem. In this work, an excitation problem of a terahertz double corrugation slow-wave structure is considered and practical realization of the structure using currently available technological processes is discussed. The parameters of the realized excitation structure are optimized for vacuum electronics applications while taking the technological constraints into account. © 2011 EurAAP. Source


Ulrici A.,University of Modena and Reggio Emilia | Ulrici A.,Consortium for Science and Technology of Materials | Calderisi M.,University of Modena and Reggio Emilia | Calderisi M.,Consortium for Science and Technology of Materials | And 5 more authors.
Lecture Notes in Electrical Engineering | Year: 2014

In order to efficiently detect four drug precursor molecules in presence of interfering species and background air, using a EC-QCLPAS sensor operating in the mid-infrared region, a complex strategy of spectral response simulation has been developed. In this context, spectra of gases from literature databases have been collected, denoised by means of the Wavelet Transform and mixed together according to a concentration matrix, which was specifically designed to represent a comprehensive combination of possible realistic cases. To scale database spectra to the appropriate concentration levels, an ad-hoc algorithm based on a sigmoidal transfer function has been used. In this way the baseline shape and intensity is preserved. Afterwards, a preliminary wavelength selection has been carried out to exclude noisy regions. The optimal range has finally been defined by maximizing the classification efficiency for all the target gases by means of Partial Least Squares-Discriminant Analysis. © 2014 Springer Science+Business Media. Source


Caiti A.,University of Genoa | Husoy T.,Kongsberg Maritime AS | Jesus S.M.,University of Algarve | Karasalo I.,Swedish Defence Research Agency | And 4 more authors.
IFAC Proceedings Volumes (IFAC-PapersOnline) | Year: 2012

The EU-funded project UAN - Underwater Acoustic Network aims at conceiving, developing and testing at sea an innovative and operational concept for integrating in a unique communication system submerged, surface and aerial sensors with the objective of protecting off-shore and coastline critical infrastructures. A crucial aspect of the project consisted in the use of autonomous underwater vehicles (AUVs) as mobile nodes in the underwater acoustic communication network. In particular, AUVs have the role of adapting the network geometry to the variation of the acoustic channel. This paper reports on the project concept and vision as well as on the progress of its various development phases. The recent at-sea successes that have been demonstrated within the UAN framework are detailed and results of the final UAN project demonstration, UAN11, held in the May of 2011, are reported. The UAN network was in operation for five continuous days with up to five nodes, of which three of them were mobile nodes. © IFAC. Source

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