10,912 research outputs found
A model for vortex formation in magnetic nanodots
We use Monte Carlo simulation to study the vortex nucleation on magnetic
nanodots at low temperature. In our simulations, we have considered a simple
microscopic two-dimensional anisotropic Heisenberg model with term to describe
the anisotropy due to the presence of the nanodot edge. We have considered the
thickness of the edge, which was not considered in previous works, introducing
a term that controls the energy associated to the edge. Our results clearly
show that the thickness of the edge has a considerable influence in the vortex
nucleation on magnetic nanodots. We have obtained the hysteresis curve for
several values of the surface anisotropy and skin depth parameter (). The
results are in excellent agreement with experimental data
Vectorial channel estimation for uplink MC-CDMA in beyond 3G wireless systems
In beyond 3G wireless systems the bandwidth
efficiency can be increased with the use of adaptive antenna
arrays. This paper focus on a key issue for adaptive antenna
arrays, that is, channel parameters estimation including
Direction-Of-Arrival (DOA). In order to estimate DOA. the
channel frequency responses for the links between the mobile
users and each of base station array elements are estimated by
pilot-aided minimum mean square error (MMSE) algorithm.
This estimator is not sensitive to the channel statistics. Based on
frequency response estimatives DOA's of impinging multipath
components to the base station are estimated by a low complex
Wlauimuni Likelihood (ML) approach. Furthermore an uplink
burst structure with specifically designed midamble field for multiuser
channel estimation in MC-CDMA is proposed. The performance is
assessed in terms of channel estimation errors for a MC-CDMA
TDD system over fast and slow fading mobile channels
Application of game theory in ad- hoc opportunistic radios
The application of mathematical analysis to the study
of wireless ad hoc networks has met with limited success due
to the complexity of mobility, traffic models and the dynamic
topology. A scenario based UMTS TDD opportunistic cellular
system with an ad hoc behaviour that operates over UMTS
FDD licensed cellular network is considered. In this paper, we
describe how ad hoc opportunistic radio can be modeled as a
game and how we apply game theory based Power Control in
ad-hoc opportunistic radio
Private-label proneness: the case of yogurts
This study aims to point out the main consumer correlates of store brand proneness in a specific
industry, the Portuguese yogurt market. This is a booming industry for store brands in Portugal,
reaching nearly half of the total market share. Based on the results of a survey we can conclude that
consumers base their decisions on adopting a product on three different types of variables: price
related variables, quality related variables and involvement with the product category related
variables. The price related and the quality related variables have the most influence on consumers
when selecting store brands of yogurts.info:eu-repo/semantics/submittedVersio
Determinantes psicográficos da adoção da marca do distribuidor: um estudo no mercado português de iogurtes
This study seeks to point out the main psychographic determinants of private-label brand proneness in a specific industry: the Portuguese yogurt market. This is a booming industry for store brands in Portugal, which account for nearly half of the total market share. An in-depth interview was held with a sales and marketing expert of the leading yogurt company in Portugal. Next, we conducted a survey targeting consumers of yogurt. Based on the results of a Tobit regression, we conclude that consumers base their decisions about private label versus national brands on three different types of variables: price-related variables, quality-related variables and variables related to involvement with the product category. Managerial implications are also discussed.info:eu-repo/semantics/publishedVersio
Characterising the fruit and vegetables consumer ethnocentrism in a Southern European country: an assesment of the reliability and validity of the CETSCALE in Portugal
This paper aims to characterize the consumer ethnocentrism (CE) and its implications
on food products evaluation in a Southern European Country-Portugal. The 10-item
version of the Consumer Ethnocentric Tendencies Scale (CETSCALE) was used. It’s
validity and dimensionality were assessed together with the ethnocentric
characteristics among fruit and vegetables consumers.
A questionnaire was conducted through Computer Assisted Phone Interviews – (CATI)
to the person responsible for the household food purchase in the two largest
Portuguese metropolitan areas Lisbon and Oporto resulting in 700 valid responses.
The food products under consideration were fruit and vegetables as they represent the
largest sales in the major retail chains and also are considered low value products.
Moreover, Portuguese consumption of fruit and vegetables is the highest considering
the European consumption.
The validity and the reliability of the CETSCALE have been confirmed as the showing a
high degree reliability. The multidimensionality of the construct has also been validated
with two factors obtained and named soft and hight ethnocentrism.
As far as authors are aware, this is the first study conducted in Portugal and
considering two specific food categories – fruit and vegetables. The present study
contributes to the ongoing debate on origin labelling in a time of increasing
globalisation markets.info:eu-repo/semantics/publishedVersio
Genetic risk scores: are they important for diabetes management? results from multiple cross-sectional studies.
Several genetic risk scores (GRS) for type 2 diabetes (T2DM) have been published, but not replicated. We aimed to 1) replicate previous findings on the association between GRS on prevalence of T2DM and 2) assess the association between GRS and T2DM management in a sample of community-dwelling people from Switzerland.
Four waves from a prospective study conducted in Lausanne. Seven GRS related to T2DM were selected, and compared between participants with and without T2DM, and between controlled and uncontrolled participants treated for T2DM.
Data from 5426, 4017, 2873 and 2170 participants from the baseline, first, second and third follow-ups, respectively, was used. In all study periods, participants with T2DM scored higher than participants without T2DM in six out of seven GRS. Data from 367, 437, 285 and 207 participants with T2DM was used. In all study periods, approximately half of participants treated for T2DM did not achieve adequate fasting blood glucose or HbA <sub>1</sub> c levels, and no difference between controlled and uncontrolled participants was found for all seven GRS. Power analyses showed that most GRS needed a sample size above 1000 to consider the difference between controlled and uncontrolled participants as statistically significant at p = 0.05.
In this study, we confirmed the association between most published GRS and diabetes. Conversely, no consistent association between GRS and diabetes control was found. Use of GRS to manage patients with T2DM in clinical practice is not justified
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