20,434 research outputs found
Online sales and business model innovation in art markets: a case study
Every year online sales represent a higher percentage of the sales total in nearly all sectors of the economy, and the art markets are no exception. However, there are few empirical studies showing how online sales and digital technologies are transforming the art markets at a micro-level. This study is based on the detailed examination of the financial performance of one of the two largest Portuguese auction houses, Cabral Moncada Leilões (CML), over a period of twelve years (2007-2018), complemented with interviews with its top-managers. It analyses a set of financial indicators (e.g., EBIT, ROA, EQUITY, sales volume, net results, etc.), along with some markers that are specific to the auction sector (e.g., average lot value, number of auctions per year, etc.). From this analysis it is possible to conclude that the deterioration of this company's financial performance was the driving force that led it to explore the potential of digital economy. In the process, its business model changed dramatically, leading the company to a different market position and to the enlargement of its national and international customer base.info:eu-repo/semantics/publishedVersio
Semi-empirical analysis of Sloan Digital Sky Survey galaxies III. How to distinguish AGN hosts
We consider the techniques to distinguish normal star forming (NSF) galaxies
and active galactic nuclei (AGN) hosts using optical spectra. The observational
data base is a set of 20000 galaxies extracted from the Sloan Digital Sky
Survey, for which we have determined the emission line intensities after
subtracting the stellar continuum obtained from spectral synthesis. Our
analysis is based on photoionization models computed using the stellar ionizing
radiation predicted by Starburst 99 and, for the AGNs, a broken power-law
spectrum. We explain why, among the four classical emission line diagnostic
diagrams, the [OIII]/Hb vs [NII]/Ha one works best. We show however, that none
of these diagrams is efficient in detecting AGNs in metal poor galaxies, should
such cases exist. We propose a new divisory line between ``pure'' NSF galaxies
and AGN hosts. We also show that a classification into NSF and AGN galaxies
using only [NII]/Ha is feasible and useful. Finally, we propose a new
classification diagram, the DEW diagram, plotting D_n(4000) vs
max(EW[OII],EW[NeIII]). This diagram can be used with optical spectra for
galaxies with redshifts up to z = 1.3, meaning an important progress over
classifications proposed up to now. Since the DEW diagram requires only a small
range in wavelength, it can also be used at even larger redshifts in suitable
atmospheric windows. It also has the advantage of not requiring stellar
synthesis analysis to subtract the stars and of allowing one to see ALL the
galaxies in the same diagram, including passive galaxies.Comment: 14 pages, 9 figures, accepted for publication in MNRAS (replaced on
august 3, 2006, eqs 6 and 7 corrected
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