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La riforma costituzionale della magistratura ordinaria
No full textLa relazione valuta i rischi per l’autonomia e l’indipendenza della magistratura nella Riforma costituzionale della magistratura ordinaria
Limit points for the spectral radii of unbalanced signed graphs
No full textThe spectral radius of a signed graph Γ = (G,σ) is the largest absolute value of its
adjacency eigenvalues. In this paper we prove that sequences of unbalanced signed graphs suffice to retrieve all the possible limit points for the spectral radii of signed graphs. In order to achieve this result it turns out to be decisive a revisiting of the celebrated Shearer’s construction of the sequence of simple
(unsigned) graphs whose index tends to a fixed real number a ⩾√︁(2 + √5). Additionally, our technique helps to detect infinite pairs of non-isomorphic cospectral pairs with unbalanced quadrangles
Encirclement of an exceptional point and eigenvalue switch in non-Hermitian coupled spintronic nano-oscillators
No full textExceptional points (EPs) are known for their unique topological behaviors, including eigenvalue and eigenvector switching and high sensitivity to parameter changes. While EPs are usually studied in parity-time (PT) symmetric systems, we investigate the presence of EPs in the more general case of purely non-Hermitian systems. Using coupled spintronic auto-oscillators with uncompensated gain/loss, we explore the parameter space of the coupled system by fine-tuning the spin-transfer torque effect and its relative phase. Using this approach, we reveal and investigate the generalized presence of EPs. These tuning mechanisms provide direct control over the coupling nature, from conservative to dissipative. Moreover, we demonstrate the topological nature of the EP by dynamical encircling it in the phase-current parameter space, resulting in a switch of the eigenvalues. Our study introduces a new and versatile approach for exploring non-Hermitian physics in spintronic systems at room temperature
L’esperienza della Collana Diritto e Religioni (Luigi Pellegrini Editore) a venti anni dalla sua fondazione
No full textLe Collane di diritto ecclesiastico e canonic
Non perdiamo la bussola: come orientarsi nella transizione scuola-università e scegliere la matematica con consapevolezza
No full textSi presenta il contributo più autonomo del Dipartimento di Matematica e Applicazioni al progetto generale di orientamento, ovvero sostenere i giovani
diplomati nel momento della difficile transizione scuola -università, per scegliere con consapevolezza un percorso di studi in matematica
Effect of ageing on the seismic risk of RC wall–frame buildings under sequential earthquakes and consequences for insurance premiums
No full textIn India, a large stock of RC wall–frame buildings with deficient structural wall plan density (SWPD) is potentially vulnerable to combined ageing-induced deterioration and repeated seismic excitation. The primary objective of the present study is to evaluate the seismic risk of such building stock and to analytically derive the insurance parameters for the risk management, considering both ageing effects and sequential ground motion (GM) records. Three levels of corrosion rate (CR) or corrosion deterioration are considered, representing severe ageing, moderate ageing, and no ageing. A performance-based framework is adopted in which nonlinear response history analyses are used to develop seismic fragility and vulnerability functions. These functions are subsequently integrated with a site-specific seismic hazard curve to estimate annual seismic damage rate and seismic financial risk. The results show that the combined influence of corrosion deterioration and sequential GMs leads to a substantial increase in annual seismic damage rate, with the maximum amplification observed at near-collapse damage state. The f inancial risk results further show that the sequential GM records increase absolute financial loss with the increase in corrosion rate; however, its relative (multiplicative) impact across different hazard levels is highest for no ageing effect (CR = 0%). Finally, using a novel approach, the insurance parameters are determined, and the effect of corrosion-induced deterioration on the annual premium rate is quantified. Overall, the findings demonstrate the importance of accounting for the coupled effects of corrosion deterioration and sequential GMs in the seismic risk evaluation of RC wall–frame building stock. The results also provide quantitative support for risk- informed mitigation strategies and insurance decision-making
Heat transfer performances of an impinging synthetic jet-controlled sweeping jet
No full textThe current work deals with the experimental analysis of the heat transfer performances of a synthetic jet-controlled jet. Specifically, this study focuses on a novel device consisting of two synthetic jets, driven in opposition of phase, controlling a main steady jet issued through a square exit nozzle, which results into a sweeping jet. Infrared thermography and a heated thin foil heat flux sensor are used to experimentally investigate the cooling performances of the jet, both in the baseline (i.e. without control) and in different controlled configurations. The synthetic jets are operated at several amplitudes and actuation frequencies, for a total of nine control configurations, characterized by different values of the momentum coefficient Cμ and the Strouhal number St. All the experiments are carried out at the same jet Reynolds number, equal to 5.79×103, while six different nozzle-to-plate distances H/D are taken into account. The time- and phase-averaged results suggest that the angle swept by the main jet widens with the increase of the synthetic jet control parameters, specifically the momentum coefficient. Consequently, at low impingement distances (H/D≤2), the configurations characterized by the largest value of Cμ outperform the steady jet in terms of heat transfer rates nearby the centre of the target surface. Differently, as the impingement distance increases (H/D≥4), the baseline configuration offers the highest heat transfer rates, although the controlled configurations yield regions of maximum convective heat transfer with greater uniformity. Furthermore, the Strouhal number affects the curvature of the jet, and consequently the shape of the region of high convective heat transfer
HOPE: Histopathological image Organization and Processing Environment
No full textIn disciplines such as digital pathology, the management of vast amounts of data, primarily ultra-high-resolution images, remains a significant barrier to the widespread adoption and seamless sharing of knowledge. Current research efforts are heavily focused on image encoding, often overlooking equally critical aspects such as indexing and efficient content transmission. Traditional compression methods, such as JPEG2000, prioritize reconstruction quality but do not inherently support direct retrieval or progressive transmission, both of which are essential for applications like telemedicine and large-scale digital pathology archives. To bridge this gap, we introduce a novel framework that integrates fractal compression, deep learning-based retrieval, and adaptive transmission, optimizing not only storage efficiency but also accessibility and scalability in histopathological imaging.
The Histopathological image Organization and Processing Environment (HOPE) framework here proposed exploits Partitioned Iterated Function Systems for image compression, achieving high compression ratios while preserving essential structural details. To mitigate the inherent artifacts of fractal compression, a U-Net autoencoder is integrated, refining decompressed images and enhancing visual quality. Additionally, a residual encoding mechanism is employed, allowing for lossless reconstruction when necessary. Unlike conventional methods, this framework enables direct retrieval from the compressed domain by extracting discriminative features from the fractal encoding coefficients. Another key innovation is its progressive transmission capability, which allows an initial low-bitrate preview to be sent, followed by incremental quality refinements based on diagnostic needs. This significantly reduces network load and enables real-time access to high-resolution histopathological images on resource-limited devices. Experimental results demonstrate that the proposed framework achieves compression performance comparable to JPEG2000, while simultaneously enabling efficient indexing, high-accuracy retrieval, and scalable transmission
Least squares with equality constraints extreme learning machines for the resolution of PDEs
No full textIn this paper, we investigate the use of single hidden-layer neural networks as a family of ansatz functions for the resolution of partial differential equations (PDEs). In particular, we train the network via Extreme Learning Machines (ELMs) on the residual of the equation collocated on -eventually randomly chosen- points. Because the approximation is done directly in the formulation, such a method falls into the framework of Physically Informed Neural Networks (PINNs) and has been named PIELM. Since its first introduction, the method has been refined variously, and one successful variant is the Extreme Theory of Functional Connections (XTFC). However, XTFC strongly takes advantage of the description of the domain as a tensor product. Our aim is to extend XTFC to domains with general shapes. The novelty of the procedure proposed in the present paper is related to the treatment of boundary conditions via constrained imposition, so that our method is named Least Squares with Equality constraints ELM (LSE-ELM). An in-depth analysis and comparison with the cited methods is performed, again with the analysis of the convergence of the method in various scenarios. We show the efficiency of the procedure both in terms of computational cost and in terms of overall accuracy