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Number of results: 6
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Abstract

A high performance distributed sensor system with multi-intrusions simultaneous detection capability based on phase sensitive OTDR (Φ−OTDR) has been proposed and demonstrated. To improve system performance, three aspects have been investigated. Firstly, a model of one−dimensional impulse response of backscattered light and a Monte Carlo method have been used to study how the laser line width affects the system performance. Theoretical and experimental results show that the performances of the system, especially the signal−noise−ratio (SNR), decrease with the broadening of laser linewidth. Secondly, a temperature−compensated fibre Bragg grating with a 3 dB linewidth of 0.05 nm and a wavelength stability of 0.1 pm has been applied as an optical filter for effective denoising. Thirdly, a novel interrogation method for multi−intrusions simultaneous detection is proposed and applied in data denoising and processing. Consequently, benefiting from the three−in−one improvement, a high performance Φ−OTDR has been realized and four simultaneous applied intrusions have been detected and located at the same time along a 14 km sensing fibre with a spatial resolution of 6 m and a high SNR of 16 dB. To the best of our knowledge, this is the most multifunctional Φ−OTDR up to now and it can be used for perimeter and/or pipeline intrusion real−time monitoring.

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Authors and Affiliations

Y. Zhan
Q. Yu
K. Wang
F. Yang
Y. Kong
X. Zhao
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Abstract

The purpose of this study is to develop mathematical models based on artificial intelligence: Models based on the support vectors regression (SVR) for drought forecast in the Ansegmir watershed (Upper Moulouya, Morocco). This study focuses on the prediction of the temporal aspect of the two drought indices (standardized precipitation index – SPI and standardized precipitation-evapotranspiration index – SPEI) using six hydro-climatic variables relating to the period 1979–2013. The model SVR3-SPI: RBF, ε = 0.004, C = 20 and γ = 1.7 for the index SPI, and the model SVR3-SPEI: RBF ε = 0.004, C = 40 and γ = 0.167 for the SPEI index are significantly better in comparison to other models SVR1, SVR2 and SVR4. The SVR model for the SPI index gave a correlation coefficient of R = 0.92, MSE = 0.17 and MAE = 0.329 for the learning phase and R = 0.90, MSE = 0.18 and MAE = 0.313 for the testing phase. As for the SPEI index, the overlay is slightly poorer only in the case of the SPI index between the observed values and the predicted ones by the SVR model. It shows a very small gap between the observed and predicted values. The correlation coefficients R = 0.88 for the learning, R = 0.86 for testing remain higher and corresponding to a quadratic error average MSE = 0.21 and MAE = 0.351 for the learning and MSE = 0.21 and MAE = 0.350 for the testing phase. The prediction of drought by SVR model remain useful and would be extremely important for drought risk management.
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Authors and Affiliations

My Hachem Bekri
1
ORCID: ORCID
Abdellah El Hmaidi
1
ORCID: ORCID
Habiba Ousmana
1
ORCID: ORCID
El Mati El Faleh
1
ORCID: ORCID
Mohamed Berrada
1
ORCID: ORCID
Kamal El Aissaoui
1
ORCID: ORCID
Ali Essahlaoui
1
ORCID: ORCID
Abdelhadi El Ouali
1
ORCID: ORCID

  1. Moulay Ismail University, Faculty of Sciences, B.P. 11201, Zitoune, 50070, Meknes, Morocco
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Abstract

The delimitation requirements for establishing archipelagic waters are relatively elastic. However, some island States, which could also be considered archipelag ie States are prevented from drawing straight archipelag ie baselines because they /all meet the rule that the ratio of water to land is between I to I and9tol.
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Authors and Affiliations

Andrzej Straburzyński
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Abstract

Fifty years after Linda Nochlin wrote her essay Why Have There Been No Great Women Artists? female artists are still struggling with limitations, a weak position in the field of art and their own dependence on others. In the text I discuss selected works of artists from Central Europe, which indicate the gender and geographical dependencies prevailing in the Western art world. Such artists as Tanja Ostojić, Anetta Mona Chisa and Lucia Tkáčova, Agata Zbylut and Aneta Grzeszykowska use diversion and mimicry strategies in their art, and the artists themselves can be described as tricksters.
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Authors and Affiliations

Izabela Kowalczyk
1
ORCID: ORCID

  1. Uniwersytet Artystyczny im. Magdaleny Abakanowicz w Poznaniu
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Abstract

Effects from adsorption of organic species on the surface of nanomaterials have been investigated. Exposure to organic contaminants during material processing, handling and environmental exposure is unavoidable during the manufacturing process of nanoscale materials. In addition, at the nanoscale, surface area to volume ratios increase and surface effects will have an increasing influence on the material properties. Experimentally measured electrical properties of gold nanowires and composition will be presented. The results indicated that C, C—O—C and C=O are adsorbed at the surface of the gold nanowires. These surface contaminants are believed to cause the increase in measured resistivity. A theoretical study was performed to investigate diffusion of these contaminants into the first surface layer, which may act as scattering mechanisms for current flow.

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Authors and Affiliations

C.M. Lilley
R. Meyer

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