Meccanismi per l'invocazione di metodo remoto in Java

La tesi si propone di effettuare uno studio del meccanismo di invocazione di metodo remoto usato dal linguaggio Java, spiegandone i dettagli implementativi a basso livello. In particolare, nel primo capitolo viene presentata l'architettura dell'RMI, nei due capitoli successivi vengono presentate le classi e interfacce dei package java.rmi e sun.rmi, e infine, nel quarto capitolo viene descritta in dettaglio l'interazione tra le varie classi durante l'invocazione di metodo remoto, durante la garbage collection e nel multi-threading delle connessioni

A roadmap for Feynman's adventures in the land of gravitation

Feynman's multifaceted contributions to gravitation, as can be inferred from several published and unpublished sources, are here reviewed. Feynman thought about this subject at least from late 1954 to the late '60s, giving several contributions to it. Even if he only published three papers on gravity, much more material is available, especially the records of his many interventions at the Chapel Hill conference in 1957, which are here analyzed in detail. There, Feynman showed that he had already developed much of his picture of gravity, and he expressed deep thoughts about fundamental issues in quantum mechanics, such as superpositions of the wave functions of macroscopic objects and the role of the observer, which were suggested by the problem of quantum gravity. Moreover, Feynman lectured on gravity several times. Besides the famous lectures given at Caltech in 1962-63, he extensively discussed this subject in a series of lectures given at the Hughes Aircraft Company in 1966-67, whose focus was astronomy and astrophysics. Here Feynman gave a somewhat simplified exposition with respect to the Caltech lectures, but with many original points. All this material allows to reconstruct a detailed picture of Feynman's ideas on gravity and of its evolution until the late sixties. The main points are that gravity, like electromagnetism, has a quantum foundation, so that classical general relativity has to be regarded as emerging from an underlying quantum theory, and that this quantum theory has to be investigated by computing physical processes, as if they were measurable. The same attitude is shown with respect to gravitational waves, as evident both from the Chapel Hill records and a letter written to V. Weisskopf. As a bonus, an original approach to gravity, which closely mimics the derivation of the Maxwell equations he gave in that period, is hinted at in the unpublished lectures.Comment: 35 pages, no figures, submittet for publicatio

Deriving electromagnetism from special relativity: A novel teaching-learning module

INTRODUCTION In this presentation, a novel teaching-learning module on electromagnetism is proposed, which finds its inspiring source in two sets of unpublished notes by R. P. Feynman (Feynman 1963, 1967-68). It relies on an ab initio derivation of Lorentz's force and Maxwell's equations from special relativity (De Luca et al., 2019), which is the opposite of the usual standard historical route. This approach works with the potentials rather than the fields from the very beginning, which implies simpler mathematics. From a methodological point of view, in order to derive electromagnetism from special relativity in a consistent way, one has to develop the latter independently from electromagnetic quantities (e.g., the speed of light), which is indeed possible as shown by some authors (see, for instance, Ugarov 1979). The key observation is that the invariance of the speed of light is not postulated from the beginning, so that the theory builds upon the idea that any interaction should have a limiting speed, which is required to be an invariant according to the principle of relativity. Then, Lorentz transformations can be derived in the usual way and depend on a parameter, the invariant speed, whose value can be fixed by experiments and identified with the speed of light only at the end. These guidelines are the basis for the development of our proposal, which is aimed at introducing electromagnetism at the advanced undergraduate level. Finally, the advantages of this approach with respect to more traditional ones are briefly discussed. A BRIEF OUTLINE OF THE MODULE The module is designed for an advanced undergraduate level, so that a basic knowledge of variational principles is required. The starting point is an alternative introduction to special relativity according to the above guidelines. For instance, it is possible to derive Lorentz transformations relying only on the requirements of relativity of inertial reference frames, homogeneity of space and time, isotropy of space and group structure. The next step consists in deriving the form of the Lorentz force from first principles, i.e., building only on the Lorentz invariance of the electric charge and on relativity. That allows one to obtain, as a further bonus, the correct transformation laws for the electric and magnetic fields under Lorentz boosts. A further key point is the introduction of the 4-potential, which allows one to generalize the least action principle of classical mechanics to the relativistic case. Upon varying the action, it is possible to get the homogeneous Maxwell equations. The derivation of non-homogeneous Maxwell equations then follows from the previous results together with one more assumption, i.e., the validity of Coulomb's law. Finally, qualitative properties and shapes of fields in various situations, as well as a bunch of more applicative topics are introduced in the usual way. REFERENCES De Luca, R., Di Mauro, M., Esposito, S. & Naddeo, A. (2019). Feynman's different approach to electromagnetism. European Journal of Physics, 40, 065205. Feynman, R. P. (1963, December 13). Alternate way to handle electrodynamics. Retrieved January 20, 2019, from      http://feynmanlectures.caltech.edu/info/other/Alternate_Way_to_Handle_Electrodynamics.html Feynman, R. P. (1967-68). Feynman Hughes Lectures. Volume 2: Relativity, Electrostatics, Electrodynamics, Matter-Wave Interactions. Notes taken and transcribed by John T. Neer. Retrieved February 8, 2019, from http://www.thehugheslectures.info/wp-content/uploads/lectures/FeynmanHughesLectures_Vol2.pdf Ugarov, V. A. (1979). Special Theory of Relativity. Paris: MIR

When physics meets biology: a less known Feynman

We discuss a less known aspect of Feynman's multifaceted scientific work, centered about his interest in molecular biology, which came out around 1959 and lasted for several years. After a quick historical reconstruction about the birth of molecular biology, we focus on Feynman's work on genetics with Robert S. Edgar in the laboratory of Max Delbruck, which was later quoted by Francis Crick and others in relevant papers, as well as in Feynman's lectures given at the Hughes Aircraft Company on biology, organic chemistry and microbiology, whose notes taken by the attendee John Neer are available. An intriguing perspective comes out about one of the most interesting scientists of the XX century.Comment: On the centenary of the birth of Richard P. Feynman (May 11, 1918 - February 15, 1988

GPGPU for track finding in High Energy Physics

The LHC experiments are designed to detect large amount of physics events produced with a very high rate. Considering the future upgrades, the data acquisition rate will become even higher and new computing paradigms must be adopted for fast data-processing: General Purpose Graphics Processing Units (GPGPU) is a novel approach based on massive parallel computing. The intense computation power provided by Graphics Processing Units (GPU) is expected to reduce the computation time and to speed-up the low-latency applications used for fast decision taking. In particular, this approach could be hence used for high-level triggering in very complex environments, like the typical inner tracking systems of the multi-purpose experiments at LHC, where a large number of charged particle tracks will be produced with the luminosity upgrade. In this article we discuss a track pattern recognition algorithm based on the Hough Transform, where a parallel approach is expected to reduce dramatically the execution time.Comment: 6 pages, 4 figures, proceedings prepared for GPU-HEP 2014 conference, submitted to DESY-PROC-201

Short-term acidification detection in soils along the northern Dráva floodplain (SW Hungary) by means of Acid Neutralising Capacity (ANC) analysis

Abstract Various methods can be used for soil acidification monitoring, which can be useful towards remediation or preventing environmental degradation. It has been demonstrated that acidification can be made evident over the span of a few years, with proper monitoring. However, a reliance on pH as a main indicator can lead to detection inadequacies, especially where soils are relatively well buffered against acidity and acid deposition is negligible. A technique employing acid-neutralising capacity (ANC) derivation was applied to cultivated and uncultivated Alluvial Meadow soils to find out whether ANC data could prove effective in determining the occurrence and degree of acidification. Sampling and lab work were carried out between 2009 and 2010 on 33 sites under various land uses. Unlike pH, ANC, soil organic matter (SOM), and cation exchange capacity (CEC) decreased significantly. ANC analysis appears to be effective in detecting acidification trends over short periods and, in contrast to previous studies, under ostensibly unremarkable conditions

WEUSEDTO—Water End USE Dataset and TOols: An open water end use consumption dataset and data analytics tools

Globalization, climate changes, innovative technologies and new human habits have increased atten- tion to water conservation and management. Therefore, behavioural studies became a key element to understand how and when water is used in residential environment. Water End USE Dataset and TOols (WEUSEDTO), an open water end use consumption dataset and data analytics tools, has been released to help researchers, water utilities and companies to test models and algorithms on real water consumption data. The dataset combines with some notebook python able to analyse high-resolution water data (data recorded with 1 sample per second) to provide several tools to manage raw data, compute statistical analysis, learn fixture usage and generate synthetic simulation models. In addition, washbasin flow data were used as a test case to illustrate the main features of WEUSEDTO: providing volume and duration of single events, classifying usages and simulating user’s behaviour

Expression pattern of estroprogestinic receptors in sinonasal inverted papilloma

open13openSerra A; Caltabiano R; Spinato G; Gallina S; Caruso S; Rapisarda V; Di Mauro P; Castro V; Conti A; Licciardello L; Maiolino L; Lanzafame S; Cocuzza SSerra, A; Caltabiano, R; Spinato, G; Gallina, S; Caruso, S; Rapisarda, V; Di Mauro, P; Castro, V; Conti, A; Licciardello, L; Maiolino, L; Lanzafame, S; Cocuzza,