Search results for "Logit"
showing 10 items of 265 documents
Enhanced multinomial logit model for the analysis of choice experiments
2012
A sector of conjoint analysis (experimental design in marketing research) is made of the so called choice experiments. In choice experiments respondents undergo a questionnaire which is nowadays mostly submitted through the internet. The questionnaire proposes to the respondent a sequence of choice sets each one including two or more profiles, being a profile a specific combination of attribute levels. The respondent selects the preferred profile for each choice set. Responses given by a sample of respondents are analysed through suitable methods aimed to eventually find the best combination of attribute levels. One method of analysis adopts the Multinomial Logit (MLN) model. In this articl…
Understanding melt generation beneath the slow-spreading Kolbeinsey Ridge using 238U, 230Th, and 231Pa excesses
2011
International audience; To examine the petrogenesis and sources of basalts from the Kolbeinsey Ridge, one of the shallowest locations along the global ridge system, we present new measurements of Nd, Sr, Hf, and Pb isotopes and U-series disequilibria on 32 axial basalts. Young Kolbeinsey basalts (full-spreading rate = 1.8 cm/yr; 67 degrees 05'-70 degrees 26'N) display ((230)Th/(238)U) 1 with ((230)Th/(238)U) from 0.95 to 1.30 and have low U (11.3-65.6 ppb) and Th (33.0 ppb-2.40 ppm) concentrations. Except for characteristic isotopic enrichment near the Jan Mayen region, the otherwise depleted Kolbeinsey basalts (e. g. (87)Sr/(86)Sr = 0.70272-0.70301, epsilon(Nd) = 8.4-10.5, epsilon(Hf) = 15…
Opening the black box of food quality in the short supply chain: Effects of conventions of quality on consumer choice
2015
In recent years new forms of food distribution organisation, known as short supply chains, have gained ground. The local nature of such distribution has positive effects on the environment and on the local economy. Consumers appear to trust the short supply chain, and it has achieved considerable success. However, the short supply chain has credence characteristics which, by their very nature, cannot be identified through a system of certification. The question we address in this paper is whether it is possible to identify the constituent elements of the credence trait in relation to food quality in the short supply chain. Our hypothesis is that the latter are linked to a range of socially …
"Intellectually exhausted and increasingly desperate" versus "flat-out false and reeks of desperation" : how the blogs of the candidates in the Ameri…
2015
Negatiivinen kampanjointi on arkipäivää kaikissa vaaleissa Yhdysvalloissa ja se on kuulunut siellä jo pitkään kampanjointiperinteisiin. Negatiivisesta kampanjoinnista on tehty paljon tutkimusta, mutta näkökulma on usein liittynyt esimerkiksi television tai internetin vaalimainontaan, siihen, miten negatiivisuus vaikuttaa äänestäjiin ja äänestysaktiivisuuteen tai mikä on negatiivisuuden kohteena. Vähemmän on tutkittu lähivuosina yleistyneiden blogien käyttöä kampanjoinnissa ja erityisesti negatiivisen kampanjoinnin välineenä. Tämä tutkimus tarkastelee sitä, kuinka Yhdysvaltain vuoden 2012 presidentinvaaliehdokkaiden, Barack Obaman ja Mitt Romneyn, kampanjablogit yrittivät luoda negatiivista …
Contrasting types of metasomatism in dunite, wehrlite and websterite xenoliths from Kimberley, South Africa
2008
Abstract Dunite, wehrlite and websterite are rare members of the mantle xenolith suite in the Kimberley kimberlites of the Kaapvaal Craton in southern Africa. All three types were originally residues of extensive melt extraction and experienced varying amounts and types of melt re-enrichment. The melt depletion event, dated by Re–Os isotope systematics at 2.9 Ga or older, is evidenced by the high Mg# (Mg/(Mg + Fe)) of silicate minerals (olivine (0.89–0.93); pyroxene (0.88–0.93); garnet (0.72–0.85)), high Cr# (Cr/(Cr + Al)) of spinel (0.53–0.84) and mostly low whole-rock SiO2, CaO and Al2O3 contents. Shortly after melt depletion, websterites were formed by reaction between depleted peridotit…
Eclogite xenoliths from the Kuruman kimberlites, South Africa: geochemical fingerprinting of deep subduction and cumulate processes☆
2004
The mineralogically diverse eclogite xenolith suite sampled by the >1.6 Ga Zero kimberlite in the Kuruman group, close to the western edge of the Kaapvaal craton consists of bimineralic eclogites, orthopyroxene-bearing eclogites with and without sanidine, and kyanite eclogites. Garnet exsolutions in clinopyroxene occur in all Zero eclogite types, and orthopyroxene and, where present, sanidine are also exsolved from clinopyroxene in orthopyroxene-bearing eclogites. Mineral thermobarometry indicates that the last P–T condition prior to the kimberlite eruption was 900–950 °C at 3.5–4.0 GPa. However, inclusions of quartz, rutile and rarely K-feldspar, plus former fluid inclusions in garnets, in…
Detection of a Ca-rich lithology in the Earth's deep (>300 km) convecting mantle
2005
Earth's deep convecting upper mantle is believed to represent a rather homogenous geochemical reservoir of spinel or garnet lherzolite with primitive major element and moderately depleted trace element composition. Only where subduction occurs is this homogeneity disrupted by a suite of rocks ranging from eclogites/garnet pyroxenites (former oceanic crust) to residual harzburgites. In addition to these well documented peridotitic and metabasaltic rocks we have now discovered the presence of a chemically distinct reservoir in the deep convecting upper mantle. In situ structural analyses (micro X-ray diffraction and micro Raman spectroscopy) and three-dimensional trace element mapping (confoc…
Assessment of subjective economic well-being in Italy
2010
Using the European Survey on Income and Living Conditions for the year 2005, we analyze the subjective economic well-being and its determinants relating to some sub-groups of Italian households by means of an Ordered Logit Model (OLM), whose dependent variable is represented by a perception variable, that is the ability of households to make ends meet. The empirical results highlight that the main determinants of subjective economic well-being are the same for the four typologies of households. The subjective economic well-being is not only related to the economic status, but it is mostly influenced by socio-demographic variables, as work and education conditions. Furthermore, the level of …
Quality attributes of cactus pear fruit and their role in consumer choice
2015
Purpose – The purpose of this paper is to detect what experience and credence quality attributes contribute to the consumer decision to consume cactus pear fruit. The authors therefore try to measure the effect of each quality attribute on consumer choice. Design/methodology/approach – As a theoretical basis, two principal quality attributes emphasised in the literature on consumer behaviour were analysed and adjusted to the specific fruit features. The empirical strategy was carried out by administering a telephone questionnaire survey of 270 interviewees who consume cactus pears in Italy. The questionnaire, consisting of 14 items expressed on a metric scale (five-point Likert scale), was…