Sulle orme del consumatore affinity analysis e knowledge visualization per il processo decisionale

L\u2019articolo analizza i reali comportamenti di acquisto dell\u2019acquirente all\u2019interno del punto vendita e individua i pattern latenti pi\uf9 significativi attraverso un\u2019analisi di affinit\ue0 di 128.364 scontrini estratti da un dataset di 715.662 transazioni effettuate in un anno. Lo studio individua le strutture associative pi\uf9 ricorrenti relativamente alla singola merceologia. Attraverso la tecnica della Market Basket Analysis \ue8 stato possibile individuare le categorie merceologiche che creano \u201cpoli d\u2019attrazione\u201d sul punto vendita stimolando acquisti di altre categorie. In particolar modo, applicando le regole associative sul punto vendita \ue8 stato possibile identificare le \u201caree calde\u201d e le \u201caree fredde\u201d. L\u2019articolo evidenzia quindi alcune riflessioni sulle strategie che possono adottare gli store manager

Extended main sequence turnoff as a common feature of Milky Way open clusters

We present photometric analysis of twelve Galactic open clusters and show that the same multiple-population phenomenon observed in Magellanic Clouds (MCs) is present in nearby open clusters. Nearly all the clusters younger than $\sim$2.5 Gyr of both MCs exhibit extended main-sequence turnoffs (eMSTOs) and all the cluster younger than $\sim$700 Myr show broadened/split main sequences (MSs). High-resolution spectroscopy has revealed that these clusters host stars with a large spread in the observed projected rotations. In addition to rotation, internal age variation is indicated as a possible responsible for the eMSTOs, making these systems the possible young counterparts of globular clusters with multiple populations. Recent work has shown that the eMSTO+broadened MSs are not a peculiarity of MCs clusters. Similar photometric features have been discovered in a few Galactic open clusters, challenging the idea that the color-magnitude diagrams (CMDs) of these systems are similar to single isochrones and opening new windows to explore the eMSTO phenomenon. We exploit photometry+proper motions from Gaia DR2 to investigate the CMDs of open clusters younger than $\sim$1.5 Gyr. Our analysis suggests that: (i) twelve open clusters show eMSTOs and/or broadened MSs, that cannot be due neither to field contamination, nor binaries; (ii) split/broadened MSs are observed in clusters younger than $\sim$700 Myr, while older objects display only an eMSTO, similarly to MCs clusters; (iii) the eMSTO, if interpreted as a pure age spread, increases with age, following the relation observed in MCs clusters and demonstrating that rotation is the responsible for this phenomenon.Comment: 17 pages, 42 figures, 1 table, accepted for publication in ApJ (31/10/2018

Multiple stellar populations in Magellanic Cloud clusters. V. The split main sequence of the young cluster NGC1866

One of the most unexpected results in the field of stellar populations of the last few years, is the discovery that some Magellanic-Cloud globular clusters younger than ~400 Myr, exhibit bimodal main sequences (MSs) in their color-magnitude diagrams (CMDs). Moreover, these young clusters host an extended main sequence turn off (eMSTO) in close analogy with what is observed in most ~1-2 Gyr old clusters of both Magellanic Clouds. We use high-precision Hubble-Space-Telescope photometry to study the young star cluster NGC1866 in the Large Magellanic Cloud. We discover an eMSTO and a split MS. The analysis of the CMD reveals that (i) the blue MS is the less populous one, hosting about one-third of the total number of MS stars; (ii) red-MS stars are more centrally concentrated than blue-MS stars; (iii) the fraction of blue-MS stars with respect to the total number of MS stars drops by a factor of ~2 in the upper MS with F814W <~19.7. The comparison between the observed CMDs and stellar models reveals that the observations are consistent with ~200 Myr old highly-rotating stars on the red-MS, with rotation close to critical value, plus a non-rotating stellar population spanning an age interval between ~140 and 220 Myr, on the blue-MS. Noticeable, neither stellar populations with different ages only, nor coeval stellar models with different rotation rates, properly reproduce the observed split MS and eMSTO. We discuss these results in the context of the eMSTO and multiple MS phenomenon.Comment: 11 pages, 11 figures, accepted for publication in MNRA

Modeling and simulation of a digital control design approach for power supply systems

Electronic designers need to model and simulate system features as close as possible to its effective behaviour. Moreover, today, electronics systems are often composed of mixed analog and digital components. The increasing complexity has led to the use of different simulation softwares, each one specific for a particular level of abstraction: mathematical, circuital, behavioural, etc. In order to simulate the entire system these softwares should work together: co-simulation is necessary for digitally controlled power electronics systems. In this paper, the modeling of a digitally controlled switching power supply system using MATLAB/Simulink, ALDEC Active-HDL and Powersys PSIM is presented. The power converter is modelled in PSIM, the digital control is described in VHDL by using Active-HDL, and the complete system is simulated in MATLAB/Simulink environment. This design approach presents all the advantages of each used software and all its features will be discussed. The comparison between simulation and experimental results of the digitally controlled step-down converter prototype are reported

PRIMI DATI SUGLI INNESTI DI ABIES NEBRODENSIS (LOJAC.) MATTEI ESEGUITI SU ABETI ESOTICI NELL\u2019AREA DI INDIGENATO (MADONIE)

C2 = PRIMI DATI SUGLI INNESTI DI ABIES NEBRODENSIS (LOJAC.) MATTEI ESEGUITI SU ABETI ESOTICI NELL\u2019AREA DI INDIGENATO (MADONIE) R. SCHICCHI, P. BONOMO, M. CANDORE, G. DI NOTO, A. PUCCI, F. TRAPANI, P. MARINO Dipartimento di Biologia Ambientale e Biodiversit\ue0 dell'Universit\ue0, via Archirafi 38, 90123 Palermo (I) [email protected] Abies nebrodensis \ue8 una specie endemica relitta, gravemente minacciata di estinzione, la cui popolazione naturale \ue8 costituita da 30 individui distribuiti discontinuamente in una piccola area del territorio di Polizzi Generosa, all\u2019interno del Parco naturale delle Madonie in Sicilia. La minaccia di estinzione \ue8 dovuta, oltre all'esiguit\ue0 della popolazione, al ridotto numero di piante mature (ventiquattro) e al pericolo di inquinamento genetico incombente. A partire dall\u2019inizio degli anni \u201880 del secolo scorso, infatti, sono stati introdotti nella vicinanze dell\u2019area di indignato individui di abeti esotici (Abies alba Mill., A. cephalonica Loudon, e A. nordmanniana (Stefen) Spach) che, avendo raggiunto la maturit\ue0 sessuale, potrebbero mettere a rischio l\u2019integrit\ue0 genetica della progenie dell\u2019abete locale (Raimondo & Schicchi, 2005). Nell\u2019ambito del progetto \u201cConservazione di Abies nebrodensis e ripristino delle torbiere di Geraci Siculo\u201d, in corso di attuazione da parte dell\u2019Ente Parco delle Madonie, del Dipartimento di Biologia ambientale e Biodiversit\ue0 di Palermo e di altri partners locali, un\u2019azione di salvaguardia prevede l\u2019innesto degli abeti esotici con marze di A. nebrodensis, valorizzando la positiva esperienza effettuata con il progetto Life Natura (1). A tal fine, nel periodo compreso tra la terza decade di aprile e la seconda decade di maggio sono stati effettuati circa 350 innesti in contrada Comunello, nel territorio di Isnello. Le marze sono state prelevate da individui maturi di A. nebrodensis di oltre 30 anni di et\ue0, introdotti nelle opere di ripopolamento che, in seguito ai risultati delle analisi genetiche, sono geneticamente correlati agli esemplari della popolazione naturale. Gli innesti sono stati eseguiti a spacco ma soprattutto a corona, previa capitozzatura dei soggetti di A. alba e A. cephalonica, a un\u2019altezza di circa 2 m per evitare possibili danneggiamenti da parte del bestiame. Nei soggetti sono stati, comunque, rilasciati temporaneamente alcuni palchi che, continuando a svolgere le normali funzioni vitali, agevoleranno l\u2019attecchimento delle marze. Queste ultime sono state opportunamente sagomate e inserite tra la corteccia e il legno sia nel fusto capitozzato che in alcuni rami laterali. Esse sono state tenute strettamente aderenti ai soggetti tramite nastro adesivo e protette da due sacchetti, rispettivamente di polietilene e di carta, per creare condizioni micro-climatiche ottimali alla sopravvivenza delle marze. Dalla terza decade di maggio \ue8 iniziato, con cadenza settimanale, il monitoraggio degli innesti e la foratura, ove necessario, del sacchetto di plastica per eliminare l\u2019umidit\ue0 in eccesso. Dopo 40 giorni \ue8 stato possibile constatare che oltre il 90% degli innesti \ue8 attecchito. Anche alcuni innesti eseguiti a scopo sperimentale su Pseudotsuga menziesii Franco sono vitali. Durante la fine di luglio e agosto si prevede una graduale scopertura delle marze. Gli esiti di questa azione, tuttavia, potranno essere valutati compiutamente all\u2019inizio della prossima primavera. La tecnica dell\u2019innesto riveste notevole importanza poich\ue9 permette di eliminare o ridurre una delle minacce pi\uf9 consistenti a carico della popolazione naturale di A. nebrodensis, trasformando la stessa in un punto di forza nell\u2019ambito della strategia di conservazione della specie. Essa, infatti, potr\ue0 contribuire a incrementare la popolazione dell\u2019endemico A. nebrodensis, valorizzando come portainnesti piante che se non abbattute costituirebbero un serio pericolo per la conservazione dell\u2019abete delle Madonie. Raimondo F. M., Schicchi R., 2005. Rendiconto sul progetto LIFE Natura n\ub0 LIFE2000NAT/IT/7228 \u201cConservazione in situ ed ex situ di Abies nebrodensis (Lojac.) Mattei\u201d. Tipolitografia Luxograph, Palermo

A matrix model for the topological string II: The spectral curve and mirror geometry

In a previous paper, we presented a matrix model reproducing the topological string partition function on an arbitrary given toric Calabi-Yau manifold. Here, we study the spectral curve of our matrix model and thus derive, upon imposing certain minimality assumptions on the spectral curve, the large volume limit of the BKMP "remodeling the B-model" conjecture, the claim that Gromov-Witten invariants of any toric Calabi-Yau 3-fold coincide with the spectral invariants of its mirror curve.Comment: 1+37 page

The monumental olive trees as biocultural heritage of mediterranean landscapes: The case study of sicily

Monumental olive trees, with their longevity and their remarkable size, represent an important information source for the comprehension of the territory where they grow and the human societies that have kept them through time. Across the centuries, olive trees are the only cultivated plants that tell the story of Mediterranean landscapes. The same as stone monuments, these green monuments represent a real Mediterranean natural and cultural heritage. The aim of this paper is to discuss the value of monumental trees as “biocultural heritage” elements and the role they play in the interpretation of the historical stratification of the landscape. We present the results of a survey of the most significant olive trees growing in Sicily. The selection was based on the “monumentality” aspects of trees, taking into account dendrometric parameters and environmental contexts. The collected dataset constitutes a heterogeneous sample of 367 specimens of considerable size that, in some cases, reach a circumference of about 19 m. Starting from the data presented here, the whole Sicilian territory shows a historical relationship between human and olive. The presence of these plant monuments is, therefore, evidence of long‐term, often centennial, landscapes as a result of sustainable use of the territory

Design of GEMSTAR tidal current fixed pitch rotor controlled through a Permanent Magnet Generator (PMG) de‐fluxing technique

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The Lithium test for multiple populations in Globular Clusters: Lithium in NGC 2808

In the globular cluster NGC2808, a quasi-standard initial lithium abundance is derived for a red giant belonging to the `extreme' population, characterized by a large helium overabundance, and by abundances of proton capture elements typical of nuclear processing in gas at very high temperatures, where the initial lithium has been fully destroyed. The observations of lithium in such extreme cluster stars are important to test different models for the formation of multiple populations in old Globular Clusters. In the asymptotic giant branch (AGB) scenario, fresh lithium is synthetized during the initial phases of hot bottom burning which, afterwards, synthetize the other p-capture elements. We model the abundance of lithium in the ejecta of superAGB models, finding values consistent or larger than observed in the `extreme' giant; these same models describe correctly the magnesium depletion and silicon enrichment of the extreme population of NGC 2808, so the overall agreement provides further support to the AGB scenario. In the models involving massive or supermassive stars, the Lithium observed requires a mixture of the lithium-free ejecta of the polluting population with more than 40% of standard-lithium pristine gas. The extended chemical anomalies of NGC 2808 stars are then to be all explained within at most 60% of the possible dilution range, the initial helium mass fraction in the ejecta should be Y >= 0.5, to account for the Ye 0.38-0.40 of the extreme population, and further observations of p-process elements are needed to check the model.Comment: accepted for publication in The Astrophysical Journal Letter