1,721,011 research outputs found
Computational aspects of robust estimators for linear regressions
No full textThis paper presents estimation procedures for some robust regression methods: the Bounded-Influence estimator for both a single linear equation (Krasker and Welsch, 1982) and a linear simultaneous equation model (Krasker and Welsch, 1985); the linear version of the Huber estimator for both a single equation (Huber, 1973, 1981) and a simultaneous equations model. The procedures are written in the RATS econometric language, which is widely available on microcomputers and mainframes. © 1989 Kluwer Academic Publishers
The finite mixture model for the tails of distribution: Monte Carlo experiment and empirical applications
No full textThe finite mixture model estimates regression coefficients distinct in each of the different groups of the dataset endogenously determined by this estimator. In what follows the analysis is extended beyond the mean, estimating the model in the tails of the conditional distribution of the dependent variable within each group. While the clustering reduces the overall heterogeneity, since the model is estimated for groups of similar observations, the analysis in the tails uncovers within groups heterogeneity and/or skewness. By integrating the endogenously determined clustering with the quantile regression analysis within each group, enhances the finite mixture models and focuses on the tail behavior of the conditional distribution of the dependent variable. A Monte Carlo experiment and two empirical applications conclude the analysis. In the well-known birthweight dataset, the finite mixture model identifies and computes the regression coefficients of different groups, each one with its own characteristics, both at the mean and in the tails. In the family expenditure data, the analysis of within and between groups heterogeneity provides interesting economic insights on price elasticities. The analysis in classes proves to be more efficient than the model estimated without clustering. By extending the finite mixture approach to the tails provides a more accurate investigation of the data, introducing a robust tool to unveil sources of within groups heterogeneity and asymmetry otherwise left undetected. It improves efficiency and explanatory power with respect to the standard OLS-based FMM
Novel TCAD oriented definition of the off-state breakdown voltage in Schottky-gate FETs: a 4H SiC MESFET case study
Full text linkPhysics-based breakdown voltage optimization in Schottky-barrier power RF and microwave field-effect transistors as well as in high-speed power-switching diodes is today an important topic in technology computer-aided design (TCAD). OFF-state breakdown threshold criteria based on the magnitude of the Schottky-barrier leakage current can be directly applied to TCAD; however, the results obtained are not accurate due to the large uncertainty in the Schottky-barrier parameters and models arising above all in advanced wide-gap semiconductors and to the need of performing high-temperature simulations to improve the numerical convergence of the model. In this paper, we suggest a novel OFF-state breakdown criterion, based on monitoring the magnitude (at the drain edge of the gate) of the electric field component parallel to the current density. The new condition is shown to be consistent with more conventional definitions and to exhibit a significantly reduced sensitivity with respect to physical parameter variation
TCAD design and optimization of field-plate SiC MESFETs for RF and microwave applications
No full textAnalysing the consumer purchasing behaviour for certified wood products in Italy
No full textSustainable or ethical consumption increases over time and involves a growing variety of products. In this research we focus on consumption of wood products with Sustainable Forestry Management certification in Italy considering two specific labels: Forest Stewardship Council and Program for the Endorsement of Forest Certification. We test the role of several attitudinal characteristic of Italian consumers on their purchasing intention with a structural equation model. We consider both direct and indirect impact of ecolabel knowledge, general environmental attitude, attitude toward environmental certification, trust in certification. The results show that all the attitudinal constructs of our model play a significant role in affecting the willingness to pay a premium price for certified wood products. This suggests that firms, policymakers, certifying organizations and all the stakeholders involved in the forestry supply chain can successfully implement targeted information campaigns on ecolabels and environmental issues to increase sustainable consumption. These strategies would also improve trust in ecolabels
Transfer matrix method modelling of inhomogeneous Schottky barrier diodes on silicon carbide
Full text linkBeyond one-size-fits-all: Consumers react differently to packaging colors and names of cultured meat in Italy
No full textCultured meat, also known as “in-vitro meat,” “clean meat,” “synthetic meat,” “lab-grown meat” and many other nomenclatures, represents one of the most recent controversial food technologies, even with its environmental benefits. Although the market success of cultured meat depends on consumers' acceptance, specific characteristics such as name and packaging color can influence consumers' perceptions and acceptance of the food product. This study assessed the impact of the name and packaging color of cultured meat on consumers' behavioral intentions toward its consumption in Italy. With the assumption that names and packaging colors affect consumers’ acceptance differently, according to their characteristics and food neophobia, this study used a finite mixture model to analyze the stimulus impacts across different groups of consumers. The results showed that food neophobia plays a relevant role in individual response to name and packaging color of cultured meat. Less neophobic consumers are more likely to be positively affected in their intentions by green color packaging and nomenclatures that least emphasize the unnaturalness of the product, such as “clean meat,” whereas neophobic consumers are more likely to be positively affected only by green color
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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