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Network Anomaly Detection Based on Burrows–Wheeler Transform and Variational Autoencoders
No full textThe effective automation of anomaly detectionmethods in network traffic
analysis extends to a wide range of domains. It can be used in network performance
monitoring and optimization, as well as in intrusion detection and prevention systems,
where it plays a crucial role in real-time identification and mitigation of cyber
threats. In this scenario, spotting previously unknown anomalous phenomena associated
with zero-day attacks is an extremely challenging task.Accordingly, we present a
simple unsupervised detection scheme leveraging the generalization power of Variational
Autoencoder and able to support packet-based detection through a novel
feature extraction approach using specific organizational properties of the Burrows–
Wheeler transform. The resulting framework appears promising in complementing
deep packet inspection practices in deep learning-based detection environments
Quasiconvex bulk and surface energies with subquadratic growth
No full textWe establish partial Hölder continuity of the gradient for equilibrium configurations of vectorial multidimensional variational problems, involving bulk and surface energies. The bulk energy densities are uniformly strictly quasiconvex functions with p-growth, 1 < p < 2, without any further structure conditions. The anisotropic surface energy is defined by means of an elliptic integrand Φ not necessarily regular
Contemporanei di lingue diverse: opacità, soggetto migrante e discorso letterario
No full textDall’«opacità» proposta dallo scrittore martinicense Édouard Glissant al «soggetto migrante» elaborato dal critico peruviano Antonio Cornejo Polar, cercherò di esplorare una fessura nel tempo presente causata da una simultaneità che non è né creolizzata né acculturata. La soggettività migrante, a quanto pare, si costruisce in uno specchio non trasparente, dove la ragione occidentale e coloniale non può riflettersi. È una soggettività che, secondo quanto proporrò, si espone a una radicale storicizzazione, metamorfosi e problematizzazione dei propri limiti. In questo studio, vedremo come la frammentazione del soggetto è persino la norma.From the “opacity” proposed by Martinican writer Édouard Glissant to the “migrant subject” elaborated by Peruvian critic Antonio Cornejo Polar, I will try to explore a fissure in present time caused by a simultaneity that is neither creolized nor acculturated. Migrant subjectivity, it seems, is constructed in a non-transparent mirror where Western and colonial reason cannot be reflected. It is a subjectivity that, according to what I will propose, exposes itself to radical historicization, metamorphosis, and problematization of its own limits. In this study, we will see how fragmentation of the subject is even the norm.De la “opacidad” propuesta por el escritor martinicano Édouard Glissant al “sujeto migrante” elaborado por el crítico peruano Antonio Cornejo Polar, intentaré explorar una fisura del tiempo presente producto de una simultaneidad que no es ni acriollada ni aculturada. La subjetividad migrante, al parecer, se construye en un espejo que no es transparente, en el cual la razón occidental y colonial no se puede reflejar. Es una subjetividad, por como propondré, se expone a una historización radical, a una metamorfosis y una problematización de los propios límites. En este estudio, veremos como la fragmentación del sujeto es la norma
Paranasal Sinus Hypoplasia and Sinonasal Anatomical Variants in Cystic Fibrosis Adult Patients: A Computed- Tomography-Based Volumetric Comparison with Healthy Controls
No full textObjectives: In this retrospective study, we performed a volumetric analysis of paranasal cavity pneumatization in a population of adult patients with cystic fibrosis compared to healthy controls, providing parcel evaluation of each sinus, and analyzing the prevalence of major anatomical sinonasal variants in the two groups. Methods: We compared paranasal sinus volumes of 89 adult patients with cystic fibrosis and 144 healthy controls who underwent paranasal sinus computed tomography. Volumes were segmented and extracted on tomographic images using the freely available software MRIcron 2019, then compared using a t-test; the z-score test was used to determine whether the two groups differ significantly in terms of major anatomical variants prevalence. Results: Overall sinus volumes in patients with cystic fibrosis patients differ significantly as compared to the healthy population (p < 0.00001). Furthermore, with the only exception of ethmoid sinus pneumatization, which was similar in both populations, all the other sinuses were statistically different. No significant difference emerged concerning anatomical variants' prevalence. Conclusions: Our results further stress the impact of cystic fibrosis on sinus structure in adult patients, better revealing the consequences of the disease on upper airways and in optimizing the management of patients with sinonasal manifestations
Nonlinear optimal control of heat pumps in electric vehicles
No full textHeat pumps can be used for thermal management of electric vehicles (EVs) in a low-cost and environmentally friendly manner. Heat pumps can exploit the heat that is diffused by the vehicle’s batteries so as to perform temperature control of the passengers cabin. A heat-pump-based thermal management system of EVs has the dual objective of (a) stabilizing temperature in the passenger cabin at the desirable levels so as to ensure the passengers’ comfort and (b) stabilizing temperature at the batteries so as to avoid degradation of the batteries’ power storage capacity and of their regenerative charging capability. So far, nonlinear model predictive control (NMPC) methods have been mainly applied for the nonlinear optimal control problem of heat pumps in EVs. In this article a novel nonlinear optimal control method is proposed for solving the nonlinear optimal control problem of heat pumps. This method is computationally simple, has clear implementation stages, and is of proven global stability. The dynamic model of the heat pump undergoes approximate linearization with the use of first-order Taylor series expansion and through the computation of the associated Jacobian matrices. Linearization takes place at each sampling instance, around a temporary operating point that is defined by the present value of the heat pump’s state vector and by the last sampled value of the control inputs vector. For the approximately linearized model of the heat pump an H-infinity stabilizing controller is designed. The feedback gains of the controller are computed through the solution of an algebraic Riccati equation, at each time step of the control method. The global stability properties of the control scheme are proven through Lyapunov analysis. Moreover, to enable state estimation-based control, the H-infinity Kalman filter is used as a robust observer. The method achieves fast and accurate tracking of reference setpoints under moderate variations of the control inputs
Intelligent Monitoring System for Construction Sites
No full textThe construction industry continues to face significant challenges in ensuring the safety of workers on construction sites. Recognized as one of the most dangerous work environments, construction sites still report high accident rates despite significant safety efforts. This paper presents a new personnel monitoring system on construction sites with the primary goal of improving safety levels and significantly decreasing the incidence of work accidents. The proposed system is an IoT hardware/software platform based on a geo-fencing system and a Deep Learning model that performs inferences on images acquired from the construction site. Specifically, key functionalities include accurate counting of workers in monitored areas and verification of the presence of personal protective equipment by each worker, while also detecting unauthorized personnel. Rigorous real-world testing has demonstrated the feasibility of the system, especially in terms of real-time operational effectiveness. The results obtained were encouraging to plan further interesting developments on the topic of construction site safety
