1,768 research outputs found
AMICO: optimized detection of galaxy clusters in photometric surveys
Get PDFWe present Adaptive Matched Identifier of Clustered Objects (AMICO), a new algorithm for the detection of galaxy clusters in photometric surveys. AMICO is based on the Optimal Filtering technique, which allows to maximize the signal-to-noise ratio (S/N) of the clusters. In this work, we focus on the new iterative approach to the extraction of cluster candidates from the map produced by the filter. In particular, we provide a definition of membership probability for the galaxies close to any cluster candidate, which allows us to remove its imprint from the map, allowing the detection of smaller structures. As demonstrated in our tests, this method allows the deblending of close-by and aligned structures in more than 50 per cent of the cases for objects at radial distance equal to 0.5 × R200 or redshift distance equal to 2 × σz, being σz the typical uncertainty of photometric redshifts. Running AMICO on mocks derived from N-body simulations and semi-analytical modelling of the galaxy evolution, we obtain a consistent mass-amplitude relation through the redshift range of 0.3 < z < 1, with a logarithmic slope of ∼0.55 and a logarithmic scatter of ∼0.14. The fraction of false detections is steeply decreasing with S/N and negligible at S/N > 5
A new implementation of an optimal filter for the detection of galaxy clusters through weak lensing
Get PDFWe developed a new version of a C++ code, Get the Halo 2021, that implements the optimal linear matched filter presented in Maturi et al.(2005).
Our aim is to detect dark matter haloes of clusters of galaxies through their weak gravitational lensing signatures applying the filter to a catalogue of simulated galaxy ellipticities. The dataset represents typical data that will be available thanks to the Euclid mission, thus we are able to forecast the filter performances on weak lensing data obtained by Euclid. The linear matched filter is optimised to maximise the signal-to-noise ratio (S/N) of the detections and minimise the number of spurious detections caused by superposition of large-scale structures; this is achieved by suppressing those spatial frequencies dominated by the large-scale structure contamination.
We compared our detections with the true population of dark matter haloes used to produce the catalogue of ellipticities. We confirmed the expectations on the filter performance raised by Maturi et al.(2005) and Pace et al.(2007). We found that S/N 7 can be considered as a reliable threshold to detect haloes through weak lensing as 83% of our detections with S/N>7 were matched to the haloes; this is consistent with Pace et al.(2007). The purity of our catalogues of detections increases as a function of S/N and reaches 100% at S/N 10.5-11. We also confirmed that the filter selects preferentially haloes with redshift between 0.2 and 0.5, that have an intermediate distance between observer and background sources, condition that maximises the lensing effects. The completeness of our catalogues is a steadily growing function of the mass until 4-5Msun/h, where it reaches values 58-68%.
Our algorithm might be used to enhance the reliability of the detections of the AMICO code (Bellagamba et al.2018), the optimal linear matched filter implemented in the Euclid data analysis pipeline to identify galaxy clusters in photometric data (Euclid Collaboration et al.2019)
TUTELA DEL LAVORO E LIBERTA' D'IMPRESA NEI PROCESSI DI ESTERNALIZZAZIONE
No full textL’elaborato analizza le conseguenze lavoristiche della successione fra imprenditori, muovendo da una ricognizione delle varie tipologie di esternalizzazione con le relative esigenze e principali criticità.
L’indagine si concentra in primo luogo sul trasferimento d’azienda, esaminando la normativa e la giurisprudenza europee per passare poi alla disciplina di diritto interno, alle procedure sindacali e a uno specifico focus sul trasferimento delle aziende in crisi.
Successivamente l’autore si sofferma sull’appalto, prendendone in particolare considerazione gli indici di genuinità, i criteri di distinzione dalla somministrazione illecita di manodopera e la tutela delle maestranze in caso di avvicendamento fra imprese.
Da ultimo, la ricerca approfondisce le c.d. “clausole sociali”, sia di prima che di seconda generazione, valutandone la compatibilità con il diritto eurounitario e con la costituzione nonché riflettendo sui possibili rimedi in caso di loro violazione.The author analyzes the labour consequences of the succession between entrepreneurs, starting from a recognition of the various types of outsourcing with the related needs and main critical issues.
The survey focuses primarily on the transfer of businesses, examining European legislation and case-law and then moving on to internal legislation, trade union procedures and a specific focus on the transfer of companies in crisis.
The author then dwells on the contract, taking into account in particular the indications of authenticity, the criteria of distinction from the illicit administration of labour and the protection of workers in the event of turnover between companies.
Finally, the research deepens the "social clauses", both first and second generation, assessing their compatibility with European law and with the constitution and reflecting on possible remedies in case of their violation
Gestione del marchio, qualità e performance economiche delle micro imprese in mercati maturi: il segmento della birra artigianale in Italia
No full textIl presente articolo illustra i risultati di una ricerca sulla relazione tra le attività di gestione della marca, la qualità dei prodotti e le performance economiche di micro imprese attive in mercati maturi. A tale scopo è svolta un’analisi in due fasi: nella prima è stata realizzata un’analisi quali-quantitativa basata su otto casi di studio approfonditi, successivamente è stato somministrato un questionario a 94 micro imprese produttrici di birra artigianale in Italia. I risultati evidenziano una relazione negativa tra l’impiego di risorse in attività di gestione della marca e la performance economica, al contrario determinata principalmente dalla qualità del prodotto offerto.Brand management, product quality and performance in micro firms operating in mature industry. The market segment of microbreweries in Italy
The paper explores the relationship between the adoption of brand management activities and economic performance in micro and small enterprises within new segments of mature markets. Both qualitative and quantitative approach have been used. Specifically, data were collected from eight case studies and a sample of 94 microbreweries operating in Italy. While a negative relationship with brand management activities is observed, economic performance is positively and significantly related with product quality
Ultra Low Carbon Vehicles: New Parameters for Automotive Design
No full textAs the influence of vehicle emissions on our environment has become better understood, the UK government has recently placed urgent emphasis on the implementation of low carbon
technologies in the automotive industry through: the UK Low Carbon Industrial Strategy. The overall objective is to offer big incentives to consumers and support for the development of infrastructure and engineering solutions. This scheme however does not consider how the development of functional and experiential user value might drive consumer demand, contributing to the adoption of low carbon vehicles (LCVs) in the mass market.
With the emergence of the North East of England as the UK’s first specialised region for the development of ultra-low carbon vehicles (ULCVs), ONE North East, as a development agency for the region's economic and business development, and Northumbria University Ideas-lab have supported a project to facilitate innovation through the collaboration of technology, research and development (R&D) and business. The High Value Low Carbon (HVLC) project aims to envisage
new user value made possible by the integration of low carbon vehicle platforms with new process and network technologies. The HVLC consortium represents vehicle manufacturers and their suppliers as well as technology based companies and through an ongoing process of design concept generation the project offers a hub for innovation led enterprise.
Whilst new technological developments in areas such as power generation, nano materials, hydrogen fuel cells, printed electronics and networked communications will all impact on future automotive design, the mass adoption of low carbon technologies represents a paradigm shift for the motorist. This paper aims to describe how the mapping of new parameters will lead to new transport scenarios that will create the space for new collaborative research on user experiences supported by innovative technologies and related services
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Matteo Maria Boiardo (1441-1494)
No full textMatteo Maria Boiardo – contemporary of Sir Thomas Malory and forerunner of Shakespeare, Spenser, Milton, Cervantes, Tolkien, and C.S. Lewis – is best known as the author of the Orlando Innamorato [Orlando in Love], a poem in ottava rima organically merging Carolingian epic and Arthurian romance. He was also a lyric and pastoral poet, playwright, and translator of classical texts into the Italian vernacular. Matteo was active in Italy during the years of 1463 throughout 1494, the year of his death
Uno sguardo all'Est. Lavoro e diritti fondamentali in Russia e negli altri Paesi della Comunità di Stati indipendenti
No full textNel contributo l'autore, dopo aver esaminato i diritti fondamentali del lavoro presenti nelle Costituzioni dei Paesi della Comunità di Stati indipendenti, si sofferma sul diritto del lavoro russo. La trattazione, a carattere diacronico, abbraccia i rami principali del diritto del lavoro: il rapporto individuale, le relazioni collettive, il mercato del lavoro. L'autore rileva una sorprendente continuità nelle linee essenziali del diritto del lavoro russo, pur nel susseguirsi di sistemi socioeconomici completamente diversi. Egli conclude che il diritto del lavoro russo appartiene saldamente alla matrice europea della materia.The contribution of the author starts by examining fundamental labour rights recognised by the Constitutions of the Countries of the Community of Independent States. Then the author focuses upon Russian Labour Law, going through the history of the main branches of the discipline: the individual relationship, industrial relations, the labour market. The article finds a surprising continuity in the essential lines of Russian Labour Law, in spite of the completely different socio-economic systems that were experimented in Russia during the twentieth century. The author concludes that Russian Labour Law clearly belongs to the European matrix of the discipline
Properties and observables of massive galaxies in self-interacting dark matter cosmologies
Get PDFWe use hydrodynamical cosmological simulations to test the differences
between cold and self-interacting dark matter models (CDM and SIDM) in the mass
range of massive galaxies
(). We consider two SIDM
models: one with constant cross section
and one where the cross section is velocity-dependent. We analyse the halo
density profiles and concentrations, comparing the predictions of
dark-matter-only and hydrodynamical simulations in all scenarios. We calculate
the best-fit Einasto profiles and compare the resulting parameters with
previous studies and define the best-fit concentration-mass relations. We find
that the inclusion of baryons reduces the differences between different dark
matter models with respect to the DM-only case. In SIDM hydro runs, deviations
from the CDM density profiles weakly depend on mass: the most massive systems
() show cored profiles, while the least massive ones
() have cuspier profiles. Finally, we compare the
predictions of our simulations to observational results, by looking at the dark
matter fractions and the distribution of strong lensing Einstein radii. We find
that in SIDM the DM-fractions decrease more rapidly with increasing stellar
mass than in CDM, leading to lower fractions at , a
distinctive signature of SIDM. At the same time, the distribution of Einstein
radii, derived from both CDM and SIDM hydro runs, is comparable to observed
samples of strong lenses with . We conclude that the
interplay between self-interaction and baryons can greatly reduce the expected
differences between CDM and SIDM models at this mass scale, and that techniques
able to separate the dark and luminous mass in the inner regions of galaxies
are needed to constrain self-interactions.Comment: 13 pages, 12 figure
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