Towards Fully Integrated Real-time Detection Framework for Online Contents Analysis - RED-Alert Approach

Social media is extensively used nowadays and is gaining popularity among the users with the increasing growth in the network capacity, connectivity, and speed. Moreover, affordable prices of data plans, especially mobile data packages, have considerably increased the use of multimedia by different users. This includes terrorists who use social media platforms to promote their ideology and intimidate their adversaries. It is therefore very important to develop automated solutions to semantically analyse online contents to assist law enforcement agencies in the preventive policing of online activities. A major challenge for the social media forensic analysis is to preserve the privacy of citizens who use online social networking platforms. This paper presents results of European H2020 project RED-Alert that aims to enable secure and privacy preserving data processing; hence the malicious content and the corresponding personality can be ethically tracked. We have mined seven social media channels for content and providing support for ten languages for analysis. Our proposed solution is designed to ensure security and policing of online contents by detecting terrorist material. We have used social network analysis, speech recognition, face and object detection besides audio event detection to extract information from online sources that are fed in a complex event processor. We have discussed the challenges and prospects of this work especially the need of analysing online contents while respecting European and national data protection laws notably GDPR

Stochastic Heterogeneity Mapping around a Mediterranean salt lens

We present the first application of Stochastic Heterogeneity Mapping based on the band-limited von Kármán function to a seismic reflection stack of a Mediterranean water eddy (meddy), a large salt lens of Mediterranean water. This process extracts two stochastic parameters directly from the reflectivity field of the seismic data: the Hurst number, which ranges from 0 to 1, and the correlation length (scale length). Lower Hurst numbers represent a richer range of high wavenumbers and correspond to a broader range of heterogeneity in reflection events. The Hurst number estimate for the top of the meddy (0.39) compares well with recent theoretical work, which required values between 0.25 and 0.5 to model internal wave surfaces in open ocean conditions based on simulating a Garrett-Munk spectrum (GM76) slope of −2. The scale lengths obtained do not fit as well to seismic reflection events as those used in other studies to model internal waves. We suggest two explanations for this discrepancy: (1) due to the fact that the stochastic parameters are derived from the reflectivity field rather than the impedance field the estimated scale lengths may be underestimated, as has been reported; and (2) because the meddy seismic image is a two-dimensional slice of a complex and dynamic three-dimensional object, the derived scale lengths are biased to the direction of flow. Nonetheless, varying stochastic parameters, which correspond to different spectral slopes in the Garrett-Munk spectrum (horizontal wavenumber spectrum), can provide an estimate of different internal wave scales from seismic data alone. We hence introduce Stochastic Heterogeneity Mapping as a novel tool in physical oceanography

A further interpretation of wisdom : maxim, aphorism, and trivia

There is so much wit and humor in this book,and i found out that wisdom is not after all too seriois to learn

High-resolution diapycnal mixing map of the Alboran Sea thermocline from seismic reflection images

The Alboran Sea is a dynamically active region where the salty and warm Mediterranean water first encounters the incoming milder and cooler Atlantic water. The interaction between these two water masses originates a set of sub-mesoscale structures and a complex sequence of processes that entail mixing close to the thermocline. Here we present a high-resolution map of the diapycnal diffusivity around the thermocline depth obtained using acoustic data recorded with a high-resolution multichannel seismic system. The map reveals a patchy thermocline, with spots of strong diapycnal mixing juxtaposed with areas of weaker mixing. The patch size is of a few kilometers in the horizontal scale and of 10–15 m in the vertical one. The comparison of the obtained maps with the original acoustic images shows that mixing tends to concentrate in areas where internal waves, which are ubiquitous in the surveyed area, become unstable and shear instabilities develop, enhancing energy transfer towards the turbulent regime. These results are also compared with others obtained using more conventional oceanographic probes. The values estimated based on the seismic data are within the ranges of values obtained from oceanographic data analysis, and they are also consistent with reference theoretical values. Overall, our results demonstrate that high-resolution seismic systems allow the remote quantification of mixing at the thermocline depth with unprecedented resolution

Seismic detection and characterization of landslides and other mass movements

International audienceSeismic methods used in the study of snow avalanches may be employed to detect and characterize landslides and other mass movements, using standard spectrogram/sonogram analysis. For snow avalanches, the spectrogram for a station that is approached by a sliding mass exhibits a triangular time/frequency signature due to an increase over time in the higher-frequency constituents. Recognition of this characteristic footprint in a spectrogram suggests a useful metric for identifying other mass-movement events such as landslides. The 1 June 2005 slide at Laguna Beach, California is examined using data obtained from the Caltech/USGS Regional Seismic Network. This event exhibits the same general spectrogram features observed in studies of Alpine snow avalanches. We propose that these features are due to the systematic relative increase in high-frequency energy transmitted to a seismometer in the path of a mass slide owing to a reduction of distance from the source signal. This phenomenon is related to the path of the waves whose high frequencies are less attenuated as they traverse shorter source-receiver paths. Entrainment of material in the course of the slide may also contribute to the triangular time/frequency signature as a consequence of the increase in the energy involved in the process; in this case the contribution would be a source effect. By applying this commonly observed characteristic to routine monitoring algorithms, along with custom adjustments for local site effects, we seek to contribute to the improvement in automatic detection and monitoring methods of landslides and other mass movements

Applicazioni in ambito urbano di interferometria differenziale

This paper describes two examples of deformation monitoring based on two complementary differential interferometric SAR (Synthetic Aperture Radar) techniques. The first application concerns a thin and elongated infrastructure, the main dike of the Port of Barcelona, while the second one regards a group of buildings in an urban area. In the first application, the dike was measured by using a Persistent Scatterers technique called Stable Point Network and implemented by Altamira Information. This application illustrates the high quality of the deformation estimated derived by this technique. The second application, which was measured by using a classical DInSAR approach and a small set of interferograms, shows the effectiveness of a simple analysis in an operational context

Interferometria SAR Differenziale per il Rilevamento delle Deformazioni

The differential interferometric SAR technique represents a powerful remote sensing tool for the monitoring of terrain deformations. The paper concisely describes the properties of the differential interferometric phase, which represents the main observation for the estimation of the deformations. Then the paper discusses the main features of a new interferometric SAR procedure which applies an integrated approach for the treatment of DInSAR observations. In particular, the interferometric SAR processing and the least squares adjustment procedure to estimate the terrain deformations velocity are described. Finally an application of the proposed procedure is illustrated over simulated data

Two radar interferometric approaches to monitor slow and fast land deformations

Differential interferometric synthetic aperture radar (DInSAR)is a deformation measurement technique that couples two interesting characteristics. First, being based on remotely sensed data it offers operational advantages, like low cost data acquisition, wide area coverage, and temporally regular acquisitions. Second, it can be based on rigorous modeling and estimation procedures, which allows some of the most advanced techniques to derive measurements with high quality standards, comparable with those of some geodetic methods. The scope of this paper is to describe two complementary approaches to measure slow from a few millimeters up to some centimeters per year and fast land deformation up to few meters per year . Emphasis is given to the description of the former approach, which requires multiple SAR images of the same phenomenon and an advanced analysis procedure. The effectiveness of both approaches is illustrated through two applications on mining areas of small spatial extent located in Spain. In one case the DInSAR capability to fully detect shape and magnitude of an unknown fast deformation phenomenon is highlighted, whereas in the second one a detailed deformation map is derived over an urban area, where deformations up to 30 mm/ year occur