搜索结果：Bollettino della Societa italiana di biologia sperimentale

The purpose of this paper is to prove directly, by an elementary method, the Poisson probability law. This proof is offered as an alternative to the more usual derivation from binomial distribution in the limit of small probabilities. The same proof is then applied to the solution of a problem in statistical mechanics. --- Lo scopo di questo articolo è dimostrare direttamente, con un metodo elementare, la legge di probabilità di Poisson. Questa dimostrazione è proposta in alternativa alla più consueta derivazione dalla distribuzione binomiale nel limite delle piccole probabilità. La stessa dimostrazione viene quindi applicata alla soluzione di un problema di meccanica statistica.

English. This document aims to study the best algorithms to verify the belonging of a specific document to a related domain by comparing different methods for calculating the distance between two vectors. This study has been made possible with the help of the structures made available by the Apache Spark framework. Starting from the study illustrated in the publication "New frontier of textual classification: Big data and distributed calculus" by Massimiliano Morrelli et al., We wanted to carry out a study on the possible implementation of a solution capable of calculating the Similarity of a sentence using the distributed environment. Italiano. Il presente documento persegue l'obiettivo di studiare gli algoritmi migliori per verificare l'appartenenza di un determinato documento a un relativo dominio tramite un confronto di diversi metodi per il calcolo della distanza fra due vettori. Tale studio è stato condotto con l'ausilio delle strutture messe a disposizione dal framework Apache Spark. Partendo dallo studio illustrato nella pubblicazione "Nuova frontiera della classificazione testuale: Big data e calcolo distribuito" di Massimiliano Morrelli et al., si è voluto realizzare uno

2025 marks the 300th birthday of Father Eliseo della Concezione, professor of Experimental Physics at the Royal Academy of Studies of Palermo. To celebrate this anniversary, the Physics and Chemistry Library of the University Library System and the Department of Physics and Chemistry - Emilio Segre' have organized several cultural activities. In the article, after a brief biographical description of Father Eliseo della Concezione, we will present the activities carried out and discuss the historical and educational aspects of Father Eliseo's work carried out during his stay at the Royal Academy of Palermo at the end of 18th century.

La teoria di Lagrange per i moti secolari delle eccentricità ed inclinazioni delle orbite planetarie si fondava su un'approssimazione, dettata in larga misura dalla complessità dei calcoli necessari, che consisteva nel considerare solo equazioni lineari. In questa memoria riprendiamo in considerazione i metodi di Lagrange alla luce della teoria della stabilità esponenziale di Nekhoroshev. Grazie agli algoritmi sviluppati negli ultimi anni e alle tecniche di manipolazione algebrica possiamo tener conto anche dei contributi non lineari alle equazioni. Come applicazione cerchiamo di determinare i tempi di stabilità per il problema dei tre corpi nel caso del Sole e dei due pianeti maggiori, Giove e Saturno, mostrando che si possono ottenere risultati realistici, ancorché non ottimali. Lagrange's theory for the secular motion of perihelia and nodes of the planetary orbits was based on consideration of a linear approssimation of the dynamical equations, compatible with the complexity of the calculations. We extend Lagrange's investigations in the light of Nekhoroshev's theory of exponential stability. Using effective algorithms recently developed and computer algebra we investigate the n

In the present thesis we study absorption spectra of spin polarized isolated systems. Thus we introduce the density functional theory (DFT) formalism and its time dependent extension (TDDFT) together with the approximation used. In particula the Casida formulation of TDDFT is described. The equations for the description of open shell systems have been implemented in the abinit code. Then we used the BeH molecule as a test case. Studying the results for this molecule we underline the limits of the commonly used approximations. In particular we discuss why the the spin symmetry of excited states is broken and we propose a rule to find which excitation energies are affected by this problem. Finally, in the last part, we discuss how a better approximation could be obtained starting from the many body perturbation theory. ----- Il lavoro della presente tesi è focalizzato sullo studio dello spettro di eccitazione di sistemi isolati spin polarizzati. Quindi vengono esposte la Density Functional Theory (DFT), la sua estensione al caso dipendente dal tempo (TDDFT) e le approssimazioni utilizzate. In particolare vien esposta la formulazione di Casida della TDDFT. Le equazioni per lo studio d

Procedural Content Generation (PCG) is powerful in creating high-quality 3D contents, yet controlling it to produce desired shapes is difficult and often requires extensive parameter tuning. Inverse Procedural Content Generation aims to automatically find the best parameters under the input condition. However, existing sampling-based and neural network-based methods still suffer from numerous sample iterations or limited controllability. In this work, we present DI-PCG, a novel and efficient method for Inverse PCG from general image conditions. At its core is a lightweight diffusion transformer model, where PCG parameters are directly treated as the denoising target and the observed images as conditions to control parameter generation. DI-PCG is efficient and effective. With only 7.6M network parameters and 30 GPU hours to train, it demonstrates superior performance in recovering parameters accurately, and generalizing well to in-the-wild images. Quantitative and qualitative experiment results validate the effectiveness of DI-PCG in inverse PCG and image-to-3D generation tasks. DI-PCG offers a promising approach for efficient inverse PCG and represents a valuable exploration step t

In the article, we will report on the recovery of a Melloni's optical bench built at the end of 1800 by the "macchinista" Filippo Caliri in the "belle époque" of Palermo. A scientific instrument of particular historical and didactic interest belonging to the collection of Liceo Classico Statale "Umberto I" of Palermo. In the article, we will discuss the technical aspects of the interventions carried out. In questo articolo discuteremo del recupero di uno strumento scientifico di particolare interesse storico-didattico appartenente alla Collezione del Liceo Classico Statale "Umberto I" di Palermo: un raro banco ottico del Melloni costruito alla fine del 1800 nella Palermo della "belle époque" dal "macchinista" Filippo Caliri. Nell'articolo discuteremo gli aspetti tecnici degli interventi conservativi effettuati.

We propose in detail Antennas for generating Nondiffracting Beams of Microwaves, for instance with frequencies of the order of few GHz, obtaining fair results even when having recourse to realistic apertures, with a quite reasonable diameter. The present proposal refers to sets of suitable annular slits. The possible applications are various, including remote sensing. The paper is in Italian. [Si propongono in dettaglio Antenne per la generazione di fasci non-diffrattivi di microonde, per frequenze ad esempio dell'ordine della decina di GHz, ottenendo discreti risultati pur ricorrendo ad antenne realistiche di diametro ridotto. La proposta e' quella di usare un set di opportuni Annular Slits. Le applicazioni possibili sono varie, includendo il remore sensing.]

With the proliferation of domain-specific models, model merging has emerged as a set of techniques that combine the capabilities of multiple models into one that can multitask without the cost of additional training. In this paper, we propose a new model merging technique, Drop and rEscaLe via sampLing with mAgnitude (DELLA-Merging), that employs a novel pruning technique, MAGPRUNE, which shows significant advantages over DARE and TIES. MAGPRUNE first ranks the parameters in order of their magnitude and assigns higher dropout probabilities (p) to parameters with lower ranks corresponding to lower magnitudes. To approximate the original embeddings, MAGPRUNE employs a rescaling operation on the parameters that survive the random dropping by 1/(1 - p). On three different expert models considered for merging (LM, Math, Code) and corresponding benchmark datasets (AlpacaEval, GSM8K, MBPP), DELLA shows an average improvement of 2.4 points over baseline methods employing delta parameter pruning (an improvement of 3.6 points over TIES, 1.2 points over DARE), and 11.1 points over the no-pruning baseline (TA). We release the source code at: https://github.com/declare-lab/della.

At the INFN laboratory in Pisa I have prepared my dissertation, which essentially concerned Montecarlo simulation of subnuclear particles decays and investigation of low-noise electronic devices for analyzing high-frequency signals. The team-work was part of NA48/EPSI experiment jointly carried out with European Organization for Nuclear Research CERN, Geneva. ----- Nell'ambito dell'esperimento NA48 in corso al CERN Super Proton Syncrothon (SPS) finalizzato a misurare la violazione diretta di CP in sistemi di particelle K0 attraverso il doppio rapporto R = [N(K_L->Pi0Pi0)]/[N(K_S->Pi0Pi0)] / [N(K_L->Pi+Pi-)]/[N(K_S->Pi+Pi-)] = 1 - 6 Re(e1/e) con una precisione di Re(e1/e) superiore a 2 * 10^-4, il lavoro di tesi si propone di effettuare una simulazione per la rivelazione dei decadimenti neutri dei K0 ed una successiva analisi dei dati raffrontando l'evento fisico generato con metodo Montecarlo e quello ricostruito. Per la misura di e1/e occorre isolare tra i vari modi di decadimento dei K quelli K_S->Pi0Pi0, K_S->Pi+Pi-, e quelli K_L->Pi0Pi0, K_L->Pi+Pi-.

We characterize type isomorphisms in the multiplicative-additive fragment of linear logic (MALL), and thus in *-autonomous categories with finite products, extending a result for the multiplicative fragment by Balat and Di Cosmo. This yields a much richer equational theory involving distributivity and cancellation laws. The unit-free case is obtained by relying on the proof-net syntax introduced by Hughes and Van Glabbeek. We use the sequent calculus to extend our results to full MALL, including all units, thanks to a study of cut-elimination and rule commutations.

We present a search for long-lived particles (LLPs) produced from kaon decay that decay to two muons inside the ICARUS neutrino detector. This channel would be a signal of hidden sector models that can address outstanding issues in particle physics such as the strong CP problem and the microphysical origin of dark matter. The search is performed with data collected in the Neutrinos at the Main Injector (NuMI) beam at Fermilab corresponding to $2.41\times 10^{20}$ protons-on-target. No new physics signal is observed, and we set world-leading limits on heavy QCD axions, as well as for the Higgs portal scalar among dedicated searches. Limits are also presented in a model-independent way applicable to any new physics model predicting the process $K\to π+S(\toμμ)$, for a long-lived particle S. This result is the first search for new physics performed with the ICARUS detector at Fermilab. It paves the way for the future program of long-lived particle searches at ICARUS.

An analysis of SNIa events in early type galaxies from the Cappellaro et al (1999) database provides conclusive evidence that the rate of type Ia Supernovae (SNe) in radio-loud galaxies is about 4 times higher than the rate measured in radio-quiet galaxies, i.e. SNIa-rate$(radio-loud galaxies) = 0.43^{+0.19}_{-0.14}h^2_{75}$ SNu as compared to SNIa-rate$(radio-quiet galaxies) = 0.11^{+0.06}_{-0.03}h^2_{75}$ SNu. The actual value of the enhancement is likely to be in the range $\sim 2-7$ (P$\sim 10^{-4}$). This finding puts on robust empirical grounds the results obtained by Della Valle & Panagia (2003) on the basis of a smaller sample of SNe. We analyse the possible causes of this result and conclude that the enhancement of SNIa explosion rate in radio-loud galaxies has the same origin as their being strong radio sources, but there is no causality link between the two phenomena. We argue that repeated episodes of interaction and/or mergers of early type galaxies with dwarf companions, on times-scale of about 1 Gyr, are responsible for inducing both strong radio activity observed in $\sim$14% of early type galaxies and to supply an adequate number of SNIa progenitors to the stel

English: If the current status of theoretical and experimental knowledge in Nuclear Physics could be reduced to a geographical chart or a planisphere, then our epoch would be in some respect comparable to the end of the Medieval age and in other to the beginning of the Reinassance: epochs in which, together with the consolidated knowledge of the Old World, there have been great and revolutionary expeditions as the discovery of America or the periplus of Cape of Good Hope, explorations aimed at reaching the limits that, along the centuries, have lead to more and more engaging scientific discoveries in more and more far away lands, ending only in the twentieth century with the complete mapping of all the continents. Nuclear Physics is living an analogous adventure on the plane of contrast... - Italian: Se lo stato attuale delle conoscenze teoriche e sperimentali della Fisica Nucleare si potesse ridurre a una carta geografica o un mappamondo, allora la nostra epoca si potrebbe paragonare per certi versi alla fine del Medioevo e per altri al Rinascimento: epoche in cui, accanto alla conoscenza consolidata del Vecchio mondo, ci furono grandi e rivoluzionarie spedizioni come la scoperta

This document summarises the current theoretical and experimental status of the di-Higgs boson production searches, and of the direct and indirect constraints on the Higgs boson self-coupling, with the wish to serve as a useful guide for the next years. The document discusses the theoretical status, including state-of-the-art predictions for di-Higgs cross sections, developments on the effective field theory approach, and studies on specific new physics scenarios that can show up in the di-Higgs final state. The status of di-Higgs searches and the direct and indirect constraints on the Higgs self-coupling at the LHC are presented, with an overview of the relevant experimental techniques, and covering all the variety of relevant signatures. Finally, the capabilities of future colliders in determining the Higgs self-coupling are addressed, comparing the projected precision that can be obtained in such facilities. The work has started as the proceedings of the Di-Higgs workshop at Colliders, held at Fermilab from the 4th to the 9th of September 2018, but it went beyond the topics discussed at that workshop and included further developments.

Even if laboratory practice is essential for all scientific branches of knowledge, it is often neglected at High School, due to lack of time and/or resources. To establish a closer contact between school and experimental sciences, the University Sapienza of Roma and the Istituto Nazionale di Fisica Nucleare (INFN) launched the Lab2Go project, with the goal of spreading laboratory practice among students and teachers in high schools.

This document contains lecture notes from the Ph.D. course given at Scuola Superiore Meridionale by Daniele Di Pietro in February 2025. The goal of the course is to provide an overview of polytopal methods, focusing on the Hybrid High-Order (HHO) method. As a starting point, we study the Crouzeix-Raviart method for a pure diffusion equation, with particular focus on its stability. We then show that, switching to a fully discrete point of view, it is possible to generalize it first to polyhedral meshes and then to arbitrary order, leading to a method that belongs to the HHO family. A study of the stability and consistency of this method reveals the need for a stabilization term, for which we identify two key properties.

The inclusive cross sections for di-hadrons of charged pions and kaons ($e^+e^- \rightarrow hhX$) in electron-positron annihilation are reported. They are obtained as a function of the total fractional energy and invariant mass for any di-hadron combination in the same hemisphere as defined by the thrust event-shape variable and its axis. Since same-hemisphere di-hadrons can be assumed to originate predominantly from the same initial parton, di-hadron fragmentation functions are probed. These di-hadron fragmentation functions are needed as an unpolarized baseline in order to quantitatively understand related spin-dependent measurements in other processes and to apply them to the extraction of quark transversity distribution functions in the nucleon. The di-hadron cross sections are obtained from a $655\,{\rm fb}^{-1}$ data sample collected at or near the $Υ(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider.

We scrutinise the evidences recently reported by the ATLAS and CMS collaborations for compatible 750 GeV resonances which appear in the di-photon channels of the two experiments in both the 8 TeV and 13 TeV datasets. Similar resonances in di-boson, di-lepton, di-jet and $t\bar t$ final states are instead not detected. After discussing the properties and the compatibility of the reported signals, we study the implications on the physics beyond the Standard Model with particular emphasis on possible scalar extensions of the theory such as singlet extensions and the two Higgs doublet models. We also analyse the significance of the new experimental indications within the frameworks of the minimal supersymmetric standard model and of technicolour models. Our results show that a simple effective singlet extension of the SM achieves phenomenological viability with a minimal number of free parameters. The minimal supersymmetric model and the two Higgs doublet model, on the other hand, cannot explain the 750 GeV di-photon excess. Compatibility with the observed signal requires the extension of the particle content of these models, for instance by heavy vector quarks in the case of the two H