Timoshenko systems with fading memory

The decay properties of the semigroup generated by a linear Timoshenko system with fading memory are discussed. Uniform stability is shown to occur within a necessary and sufficient condition on the memory kernel

An Advanced Technique for User Identification Using Partial Fingerprint

User identification is a very interesting and complex task. Invasive biometrics is based on traits uniqueness and immutability over time. In forensic field, fingerprints have always been considered an essential element for personal recognition. The traditional issue is focused on full fingerprint images matching. In this paper an advanced technique for personal recognition based on partial fingerprint is proposed. This system is based on fingerprint local analysis and micro-features, endpoints and bifurcations, extraction. The proposed approach starts from minutiae extraction from a partial fingerprint image and ends with the final matching score between fingerprint pairs. The computation of likelihood ratios in fingerprint identification is computed by trying every possible overlapping of the partial image with complete image. The first experimental results conducted on the PolyU (Hong Kong Polytechnic University) free database show an encouraging performance in terms of identification accuracy

An Embedded Biometric Sensor for Ubiquitous Authentication

Communication networks and distributed technologies move people towards the era of ubiquitous computing. An ubiquitous environment needs many authentication sensors for users recognition, in order to provide a secure infrastructure for both user access to resources and services and information management. Today the security requirements must ensure secure and trusted user information to protect sensitive data resource access and they could be used for user traceability inside the platform. Conventional authentication systems, based on username and password, are in crisis since they are not able to guarantee a suitable security level for several applications. Biometric authentication systems represent a valid alternative to the conventional authentication systems providing a flexible einfrastructure towards an integrated solution supporting the requirement for improved inter-organizational functionality. In this work the study and the implementation of a fingerprintsbased embedded biometric system is proposed. Typical strategies implemented in Identity Management Systems could be useful to protect biometric information. The proposed sensor can be seen as a self-contained sensor: it performs the all elaboration steps on board, a necessary requisite to strengthen security, so that sensible data are securely managed and stored inside the sensor, without any data leaking out. The sensor has been prototyped via an FPGA-based platform achieving fast execution time and a good final throughput. Resources used, elaboration times of the sensor are reported. Finally, recognition rates of the proposed embedded biometric sensor have been evaluated considering three different databases: the FVC2002 reference database, the CSAI/Biometrika proprietary database, and the CSAI/Secugen proprietary database. The best achieved FAR and FRR indexes are respectively 1.07% and 8.33%, with an elaboration time of 183.32 ms and a working frequency of 22.5 MHz

Eating in extreme environment: diet of the European hare (Lepus europaeus) on Vesuvius

The European hare (Lepus europaeus) is cosmopolitan species, living in a variety of habitats and showing a diversified diet, that has been described mainly from agricultural meadows and crops, with little information available for extreme environments. Here, we describe, for the first time, the diet of the European hare from Mount Vesuvius, using DNA metabarcoding and high- throughput sequencing on DNA extracted from faecal pellets, a proxy for a population living in a volcanic environment. The DNA from pellets was first genetically assigned to European hare using high-resolution melting analysis. The diet of the hare on Vesuvius is mainly composed of herbaceous species belonging to Fabaceae (86.26% of total diet). The most frequent plant items ingested by the species are Galega officinalis and Lupinus angustifolius (67.10% of total diet), although these are detected only sporadically in the study area. Indeed, the spectrum of available plants also includes other easily accessible wild (i.e. Lolium sp., Bromus sp., Rumex sp.) and cultivated (i.e. Solanum lycopersicum, Cucumis melo, Pisum sativum) plant items, found only in traces in the diet of the hares. Our contribution adds information on the trophic ecology of the European hare, exploring its ability to live in an extreme environment. This could be useful to set a management strategy for conservation of the species, which is ecologically relevant on Vesuvius as prey for birds and mammals, as well as a vegetation modulator via selective grazing by endozoochory. Furthermore, our study represents the latest information on the diet of the hare living in an environment that no longer exists: an extensive fire destroyed about 80% of the woody area after our sampling. The post-fire regrowth is transforming the original environment and consequently the trophic availability for the European hare

Effects of intra-layer correlations on electron-hole double-layer superfluidity

We investigate the correlations acting within the layers in a superfluid system of electron-hole spatially separated layers. In this system of quasi-dipoles, the dominant correlations are Hartree--Fock. We find in the BEC regime of the superfluid where screening is negligible, that the effect of the correlations on superfluid properties is also negligible. However, in the BCS-BEC crossover regime, where the screening plays a crucial role, we find that the superfluid gap is significantly weakened because the correlations significantly boost the number of low-energy particle-hole excitations participating in the screening process. Finally, the intralayer correlations are found in this system to suppress a predicted phenomenon in which the average pair size passes through a minimum as the crossover regime is traversed. In the presence of intralayer correlations, the minimum is either extremely weak or completely absent

Geology of the ‘Coltre della Val Marecchia’ (Romagna-Marche Northern Apennines, Italy)

A detailed geological map at 1:50,000 scale of the Marecchia Valley and adjoining areas (Northern Apennines, NA, Italy) is presented here. The Marecchia Valley represents a geological ‘unicum’ for the NA and it has been the focus of scientific debate for a long time, due to the occurrence in the area of the ‘Coltre della Val Marecchia (CVM)’, a complex stack of allochthonous and semi-allochthonous units emplaced in a foredeep basin during the Late Miocene to Early Pliocene. In order to clarify the geological evolution for this area, the lithostratigraphic relationships and the tectonic framework have been studied, allowing better understanding of the complex relationships between tectonics and sedimentation. The main result has been a new evolutionary framework for this sector of the orogen during the Late Miocene-Early Pliocene. Several new findings about the geological-structural setting and stratigraphy, result from the geological map presented here. These are overall supported by stratigraphic and tectonic evidence, which suggest time and modes of the CVM allochthonous emplacement within the Messinian-early Pliocene foredeep successions. Relationships between the allochthonous and autochthonous formations allowed recognition of two different bodies in the CVM, gravitationally emplaced following different trajectories and timing

Josephson effect as signature of electron-hole superfluidity in bilayers of van der Waals heterostructures

We investigate a Josephson junction in an electron-hole superfluid in a double layer TMD heterostructure. Observation of a critical tunneling current is a clear signature of superfluidity. In addition, we find the BCS-BEC crossover physics in the narrow barrier region controls the critical current across the entire system. The corresponding critical velocity, which is measurable in this system, has a maximum when the excitations pass from bosonic to fermionic. Remarkably, this occurs for the density at the boundary of the BEC to BCS-BEC crossover regime determined from the condensate fraction. This provides, for the first time in a semiconductor system, an experimental way to determine the position of this boundary

Monitoring social distancing with single image depth estimation

The recent pandemic emergency raised many challenges regarding the countermeasures aimed at containing the virus spread, and constraining the minimum distance between people resulted in one of the most effective strategies. Thus, the implementation of autonomous systems capable of monitoring the so-called social distance gained much interest. In this paper, we aim to address this task leveraging a single RGB frame without additional depth sensors. In contrast to existing single-image alternatives failing when ground localization is not available, we rely on single image depth estimation to perceive the 3D structure of the observed scene and estimate the distance between people. During the setup phase, a straightforward calibration procedure, leveraging a scale-aware SLAM algorithm available even on consumer smartphones, allows us to address the scale ambiguity affecting single image depth estimation. We validate our approach through indoor and outdoor images employing a calibrated LiDAR + RGB camera asset. Experimental results highlight that our proposal enables sufficiently reliable estimation of the inter-personal distance to monitor social distancing effectively. This fact confirms that despite its intrinsic ambiguity, if appropriately driven single image depth estimation can be a viable alternative to other depth perception techniques, more expensive and not always feasible in practical applications. Our evaluation also highlights that our framework can run reasonably fast and comparably to competitors, even on pure CPU systems. Moreover, its practical deployment on low-power systems is around the corner.Comment: Accepted for pubblication on IEEE Transactions on Emerging Topics in Computational Intelligence (TETCI

a multibody simulation of a human fall model creation and validation

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