Extended LaSalle's invariance principle for full-range cellular neural networks

In several relevant applications to the solution of signal processing tasks in real time, a cellular neural network (CNN) is required to be convergent, that is, each solution should tend toward some equilibrium point. The paper develops a Lyapunov method, which is based on a generalized version of LaSalle's invariance principle, for studying convergence and stability of the differential inclusions modeling the dynamics of the full-range (FR) model of CNNs. The applicability of the method is demonstrated by obtaining a rigorous proof of convergence for symmetric FR-CNNs. The proof, which is a direct consequence of the fact that a symmetric FR-CNN admits a strict Lyapunov function, is much more simple than the corresponding proof of convergence for symmetric standard CNNs

Detection of new Misaligned Active Galactic Nuclei in the Fermi-LAT Fourth Source Catalog using machine learning techniques

Active galactic nuclei (AGN) are the most luminous and abundant objects in the γ-ray sky. AGN with jets misaligned along the line-of-sight (MAGN) appear fainter than the brighter blazars, but are expected more numerous. Fermi Large Area Telescope (LAT) detected 40 MAGNs compared to 1943 blazars. The aim of this study is to identify new MAGN candidates in the blazars of uncertain type (BCUs) listed in the Fermi-LAT 10-year Source Catalog using an artificial neural network (ANN). The statistical tests applied to the trained ANN reveals that a classification with machine learning techniques is feasible with high accuracy and precision. The trained ANN has been applied to the 1120 BCUs which have been classified into 655 BL Lacs and 314 flat spectrum radio quasars (FSRQs). Among the re-classified BCUs, the possible MAGN candidates have been determined by applying thresholds on the spectral index, variability index and gamma-ray luminosity. Our results led to 36 possible MAGN candidates, which respect the main physical properties of the 40 MAGN already listed in the Fourth Fermi Catalog

Le secret et Polichinelle, ou cultures et pratiques de la clandestinité politique à Naples au début du XIXe siècle (1799-1821)

La thèse se concentre sur l’étude de la clandestinité politique dans le Sud italien pendant les premiers vingt ans du XIXe siècle. Celle-ci tente de renouveler une historiographie qui, par manque de source directes et difficulté d’analyse, était statique depuis la première moitié du XXe siècle.Le public restreint auquel le message des sociétés secrètes était adressé et la volonté explicite de cacher ses mouvements ont, en effet, constitué un défi méthodologique non négligeable. Cela a demandé un grand travail de contextualisation sur les sources issues des organes de répression, souvent peu précises et biaisées par la psychose du complot.Le tableau qui sort du travail de recherche montre la clandestinité comme une arme choisie par les partisans de toutes les positions politiques mais qui s’avère être généralement inefficace pour sortir de la marginalisation politique et influencer les décisions du pouvoir.The thesis focuses on the history of political secrecy in Southern Italy at the beginning of XIXth century. The historiography on this subject, due to the lack of direct sources and the difficulties of interpretation, had not been renewed since the first half of XXth century.The methodological work was hardened by the particular nature of the documents: addressed to a very small public and, by definition, difficult to be found. Hence, it has been necessary to contextualise carefully every single source produced by the political polices, often misguided by conspiracy theories.The final results show that all the actors, irrespective of ideologies, have used secret in politics but it has turned out to be quit an ineffective instrument, since almost no one of them has managed to actually influence the power in place

Sexing up the international

This thesis takes sexuality as its subject matter and uses a methodology informed by postcolonial studies to explore new possibilities for thinking about the international, its construction, and its contemporary politics. I argue that postcolonial readings of sexuality can impel us to rethink the meanings and politics of international theory and to challenge notions that have come to appear fixed and unchanging. The thesis canvasses how such an intervention might occur – calling especially for a focus on the local and the everyday – and considers both the utility and the limits of the contributions sexuality might make to a rethinking of international theory. My arguments are made with reference to a series of specific examples from contemporary East and Southeast Asia: the nationalistically imbued gendered and sexed figures of the national serviceman and the Singapore Girl in Singapore; the political and social repercussions of the trial of former Malaysian Deputy Prime Minister Anwar Ibrahim on charges of sodomy; newly emerging homosexual identities in Hong Kong; and the connections between sexuality and disease that inform the Thai response to HIV/AIDS. These case studies exemplify some of the ways in which sexuality can work to recast traditional scholarly understandings of the international. They also illuminate a series of aspects that shape the encounter between sexuality and the international, encompassing issues of nationalism, globalization, metaphor, spatiality and knowledge politics. Through my analysis of these issues, I argue for a broadening out of the source materials that inform knowledge about the international and the pursuit of alternative modes of reading processes of international change and exchange. I contend that scholarship of the international needs to pay more attention to instances where the borders separating everyday, national and international spaces break down, and where we might detect new forms of knowledge about the nature, politics and functioning of the international realm

Complete Stability of Neural Networks With Extended Memristors

The article considers a large class of delayed neural networks (NNs) with extended memristors obeying the Stanford model. This is a widely used and popular model that accurately describes the switching dynamics of real nonvolatile memristor devices implemented in nanotechnology. The article studies via the Lyapunov method complete stability (CS), i.e., convergence of trajectories in the presence of multiple equilibrium points (EPs), for delayed NNs with Stanford memristors. The obtained conditions for CS are robust with respect to variations of the interconnections and they hold for any value of the concentrated delay. Moreover, they can be checked either numerically, via a linear matrix inequality (LMI), or analytically, via the concept of Lyapunov diagonally stable (LDS) matrices. The conditions ensure that at the end of the transient capacitor voltages and NN power vanish. In turn, this leads to advantages in terms of power consumption. This notwithstanding, the nonvolatile memristors can retain the result of computation in accordance with the in-memory computing principle. The results are verified and illustrated via numerical simulations. From a methodological viewpoint, the article faces new challenges to prove CS since due to the presence of nonvolatile memristors the NNs possess a continuum of nonisolated EPs. Also, for physical reasons, the memristor state variables are constrained to lie in some given intervals so that the dynamics of the NNs need to be modeled via a class of differential inclusions named differential variational inequalities

Convergence of Neural Networks with a Class of Real Memristors with Rectifying Characteristics

The paper considers a neural network with a class of real extended memristors obtained via the parallel connection of an ideal memristor and a nonlinear resistor. The resistor has the same rectifying characteristic for the current as that used in relevant models in the literature to account for diode-like effects at the interface between the memristor metal and insulating material. The paper proves some fundamental results on the trajectory convergence of this class of real memristor neural networks under the assumption that the interconnection matrix satisfies some symmetry conditions. First of all, the paper shows that, while in the case of neural networks with ideal memristors, it is possible to explicitly find functions of the state variables that are invariants of motions, the same functions can be used as Lyapunov functions that decrease along the trajectories in the case of real memristors with rectifying characteristics. This fundamental property is then used to study convergence by means of a reduction-of-order technique in combination with a Lyapunov approach. The theoretical predictions are verified via numerical simulations, and the convergence results are illustrated via the applications of real memristor neural networks to the solution of some image processing tasks in real time

Simulation of multistage compressor at off-design conditions

Computational fluid dynamics (CFD) has been widely used for compressor design, yet the prediction of performance and stage matching for multistage, high-speed machines remains challenging. This paper presents the authors' effort to improve the reliability of CFD in multistage compressor simulations. The endwall features (e.g., blade filet and shape of the platform edge) are meshed with minimal approximations. Turbulence models with linear and nonlinear eddy viscosity models are assessed. The nonlinear eddy viscosity model predicts a higher production of turbulent kinetic energy in the passages, especially close to the endwall region. This results in a more accurate prediction of the choked mass flow and the shape of total pressure profiles close to the hub. The nonlinear viscosity model generally shows an improvement on its linear counterparts based on the comparisons with the rig data. For geometrical details, truncated filet leads to thicker boundary layer on the filet and reduced mass flow and efficiency. Shroud cavities are found to be essential to predict the right blockage and the flow details close to the hub. At the part speed, the computations without the shroud cavities fail to predict the major flow features in the passage, and this leads to inaccurate predictions of mass flow and shapes of the compressor characteristic. The paper demonstrates that an accurate representation of the endwall geometry and an effective turbulence model, together with a good quality and sufficiently refined grid, result in a credible prediction of compressor matching and performance with steady-state mixing planes.</p

New determination of the production cross section for γ\gamma rays in the Galaxy

The flux of $\gamma$ rays is measured with unprecedented accuracy by the $\textit{Fermi}$ Large Area Telescope from 100 MeV to almost 1 TeV. In the future, the Cherenkov Telescope Array will have the capability to measure photons up to 100 TeV. To accurately interpret this data, precise predictions of the production processes, specifically the cross section for the production of photons from the interaction of cosmic-ray protons and helium with atoms of the ISM, are necessary. In this study, we determine new analytical functions describing the Lorentz-invariant cross section for $\gamma$-ray production in hadronic collisions. We utilize the limited total cross section data for $\pi^0$ production channels and supplement this information by drawing on our previous analyses of charged pion production to infer missing details. In this context, we highlight the need for new data on $\pi^0$ production. Our predictions include the cross sections for all production channels that contribute down to the 0.5% level of the final cross section, namely $\eta$, $K^+$, $K^-$, $K^0_S$, and $K^0_L$ mesons as well as $\Lambda$, $\Sigma$, and $\Xi$ baryons. We determine the total differential cross section $d\sigma(p+p\rightarrow \gamma+X)/dE_{\gamma}$ from 10 MeV to 100 TeV with an uncertainty of 10% below 10 GeV of $\gamma$-ray energies, increasing to 20% at the TeV energies. We provide numerical tables and a script for the community to access our energy-differential cross sections, which are provided for incident proton (nuclei) energies from 0.1 to $10^7$ GeV (GeV/n).Comment: 12 pages, 8 figures. This version includes also the fit to the LHCf data on $\pi^0$ production. It matches version published by PRD. The updated tables of the energy differential cross sections of gamma rays can be found here: https://github.com/lucaorusa/gamma_cross_sectio