398 research outputs found
Consumer attitudes and preference exploration towards fresh-cut salads using best–worst scaling and latent class analysis
This research explored the preferences and buying habits of a sample of 620 consumers of fresh-cut, ready-to-eat salads. A best–worst scaling approach was used to measure the level of preference stated by individuals regarding 12 attributes for quality (intrinsic, extrinsic and credence) of fresh-cut salads. The experiment was carried out through direct interviews at several large-scale retail outlets in the Turin metropolitan area (north-west of Italy). Out of the total number of questioned consumers, 35% said they did not consume fresh-cut salads. On the contrary, the rest of the involved sample expressed the highest degree of preference towards the freshness/appearance attribute, followed by the expiration date and the brand. On the contrary, attributes such as price, organic certification and food safety did not emerge as discriminating factors in consumer choices. Additionally, five clusters of consumers were identified, whose preferences are related both to purchasing styles and socio-demographic variables. In conclusion, this research has highlighted the positive attitude of consumers towards quality products backed by a brand, providing ideas for companies to improve within this sector and implement strategies to answer the needs of a new segment of consumers, by determining market opportunities that aim to strengthen local brands
Stellar magnetic field parameters from a Bayesian analysis of high-resolution spectropolarimetric observations
In this paper we describe a Bayesian statistical method designed to infer the
magnetic properties of stars observed using high-resolution circular
spectropolarimetry in the context of large surveys. This approach is well
suited for analysing stars for which the stellar rotation period is not known,
and therefore the rotational phases of the observations are ambiguous. The
model assumes that the magnetic observations correspond to a dipole oblique
rotator, a situation commonly encountered in intermediate and high-mass stars.
Using reasonable assumptions regarding the model parameter prior probability
density distributions, the Bayesian algorithm determines the posterior
probability densities corresponding to the surface magnetic field geometry and
strength by performing a comparison between the observed and computed Stokes V
profiles.
Based on the results of numerical simulations, we conclude that this method
yields a useful estimate of the surface dipole field strength based on a small
number (i.e. 1 or 2) of observations. On the other hand, the method provides
only weak constraints on the dipole geometry. The odds ratio, a parameter
computed by the algorithm that quantifies the relative appropriateness of the
magnetic dipole model versus the non-magnetic model, provides a more sensitive
diagnostic of the presence of weak magnetic signals embedded in noise than
traditional techniques.
To illustrate the application of the technique to real data, we analyse seven
ESPaDOnS and Narval observations of the early B-type magnetic star LP Ori.
Insufficient information is available to determine the rotational period of the
star and therefore the phase of the data; hence traditional modelling
techniques fail to infer the dipole strength. In contrast, the Bayesian method
allows a robust determination of the dipole polar strength,
G.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical
Societ
Observations of radio pulses from CU Virginis
The magnetic chemically peculiar star CU Virginis is a unique astrophysical
laboratory for stellar magnetospheres and coherent emission processes. It is
the only known main sequence star to emit a radio pulse every rotation period.
Here we report on new observations of the CU Virginis pulse profile in the 13
and 20\,cm radio bands. The profile is known to be characterised by two peaks
of 100 circularly polarised emission that are thought to arise in an
electron-cyclotron maser mechanism. We find that the trailing peak is stable at
both 13 and 20\,cm, whereas the leading peak is intermittent at 13\,cm. Our
measured pulse arrival times confirm the discrepancy previously reported
between the putative stellar rotation rates measured with optical data and with
radio observations. We suggest that this period discrepancy might be caused by
an unknown companion or by instabilities in the emission region. Regular
long-term pulse timing and simultaneous multi-wavelength observations are
essential to clarify the behaviour of this emerging class of transient radio
source.Comment: Accepted by MNRAS Letters; 5 pages, 2 figures, 3 table
- …