3,762 research outputs found
The pecuniary and non-pecuniary costs of job displacement. An evaluation of the post-displacement injury rate
This paper investigates the pecuniary and non-pecuniary costs of involuntary job loss by focusing on both post-displacement earnings losses and injury rates. To this end we employ a unique dataset. Administrative data from Italy describing individual work histories have been merged with individual data on workplace injuries. Propensity score matching techniques are employed to measure the causal effect of displacement on workplace injury rates. We find that in a period marked by tight labour market, re-employed displaced workers experience only moderate and short-lived earnings losses but are about 70 percent more likely to be injured at their subsequent jobs compared to the control group of non-displaced workers. These results suggest that re-employed displaced workers may trade pecuniary job attributes for non-pecuniary ones.Job displacement, post-displacement injury rates, propensity score matching
Organic vs local claims: substitutes or complements for wine consumers? A marketing analysis with a discrete choice experiment
This study aims to understand people's preferences concerning five different extrinsic characteristics of wine and among them organic production. Consumers' preferences were assessed by means of a choice experiment on a sample of people living in Friuli-Venezia-Giulia (north-eastern Italy). The wines considered in the hypothetical market were differentiated considering the area of origin, landscape features, production method (organic or conventional), wine denomination of origin label and price. According to our results, denomination of origin labelling is the most important factor considered by all respondents. More than one quarter of the sample is interested in purchasing organic wine and willing to pay more for it. In this respect, organic production combined with a good communication strategy in order to increase the knowledge about its benefits can be a good marketing diversification strategy. Therefore, organic production seems to be a necessary (for at least 27% of people) but not sufficient condition in characterizing wine quality: it should be supported by an appropriate promotion of the product characteristics
Multiplexity and multireciprocity in directed multiplexes
Real-world multi-layer networks feature nontrivial dependencies among links
of different layers. Here we argue that, if links are directed, dependencies
are twofold. Besides the ordinary tendency of links of different layers to
align as the result of `multiplexity', there is also a tendency to anti-align
as the result of what we call `multireciprocity', i.e. the fact that links in
one layer can be reciprocated by \emph{opposite} links in a different layer.
Multireciprocity generalizes the scalar definition of single-layer reciprocity
to that of a square matrix involving all pairs of layers. We introduce
multiplexity and multireciprocity matrices for both binary and weighted
multiplexes and validate their statistical significance against maximum-entropy
null models that filter out the effects of node heterogeneity. We then perform
a detailed empirical analysis of the World Trade Multiplex (WTM), representing
the import-export relationships between world countries in different
commodities. We show that the WTM exhibits strong multiplexity and
multireciprocity, an effect which is however largely encoded into the degree or
strength sequences of individual layers. The residual effects are still
significant and allow to classify pairs of commodities according to their
tendency to be traded together in the same direction and/or in opposite ones.
We also find that the multireciprocity of the WTM is significantly lower than
the usual reciprocity measured on the aggregate network. Moreover, layers with
low (high) internal reciprocity are embedded within sets of layers with
comparably low (high) mutual multireciprocity. This suggests that, in the WTM,
reciprocity is inherent to groups of related commodities rather than to
individual commodities. We discuss the implications for international trade
research focusing on product taxonomies, the product space, and
fitness/complexity metrics.Comment: 20 pages, 8 figure
The role of distances in the World Trade Web
In the economic literature, geographic distances are considered fundamental
factors to be included in any theoretical model whose aim is the quantification
of the trade between countries. Quantitatively, distances enter into the
so-called gravity models that successfully predict the weight of non-zero trade
flows. However, it has been recently shown that gravity models fail to
reproduce the binary topology of the World Trade Web. In this paper a different
approach is presented: the formalism of exponential random graphs is used and
the distances are treated as constraints, to be imposed on a previously chosen
ensemble of graphs. Then, the information encoded in the geographical distances
is used to explain the binary structure of the World Trade Web, by testing it
on the degree-degree correlations and the reciprocity structure. This leads to
the definition of a novel null model that combines spatial and non-spatial
effects. The effectiveness of spatial constraints is compared to that of
nonspatial ones by means of the Akaike Information Criterion and the Bayesian
Information Criterion. Even if it is commonly believed that the World Trade Web
is strongly dependent on the distances, what emerges from our analysis is that
distances do not play a crucial role in shaping the World Trade Web binary
structure and that the information encoded into the reciprocity is far more
useful in explaining the observed patterns.Comment: Preprint, accepted for SITIS 2012 (http://www.sitis-conf.org/). Final
version to be published by IEEE Computer Society as conference proceeding
Proper orthogonal decomposition, dynamic mode decomposition, wavelet and cross wavelet analysis of a sloshing flow
Internal hydrodynamics and its coupling with structural dynamics are non-negligible processes in the design phase of aerospace systems. An improved understanding of the nature of this coupling would allow for greater flexibility in modeling and design of such systems, and could lead eventually to the development of suitable active and/or passive control strategies for enhanced performances. In this manuscript we apply a number of data analysis techniques: proper orthogonal decomposition, dynamic mode decomposition and wavelet transform and their combination to time-resolved images of a liquid sloshing within an enclosure. We use these techniques to identify fluid-dynamic modes in space and time and to verify their coupling with the structural dynamics of vibrating structures. In particular we consider the transient case of a water tank mounted on a free oscillating cantilever. As the acceleration amplitude decays, we observe and quantify the transition from incoherent flow to standing waves. Our results show that the content of the images is very informative and can be used for quantitative analysis. As the main outcome, the hydrodynamic modes are identified using POD and DMD, and related to known features of sloshing flow, such as the frequency of the first symmetric free surface mode. Additionally we perform a comparison of wavelet transforms of POD time coefficients and measured acceleration signals at the tank base. Viewing the latter as the input and the former as the output of the fluid-dynamic system, we are able to correlate the enhanced damping of the cantilever oscillation to the different regimes of the hydrodynamic field
A COMPARISON BETWEEN EXPERIMENTAL AND NUMERICAL ANALYSIS OF A WELLS TURBINE
Wave energy is one of the renewable energy sources with the highest potential. Several pilot plants have been built based on the principle of the Oscillating Water Column (OWC). Among the different solutions that have been suggested, the Wells turbine has gained particular attention due to its simplicity and reliability. The majority of available studies concentrate on the steady operation of the Wells turbine, while only few analyze its performance under an unsteady and bi-directional air flow, as determined by the presence of the OWC system. In this work, experimental and numerical performance of a high-solidity Wells turbine with NACA0015 profiles under the bi-directional flow generated by a hydraulic piston is compared. The numerical simulations have been conducted using commercial CFD software and focus on unsteady predictions, with particular attention to the behavior of the flow upstream and down-stream of the rotor, flow hysteresis between acceleration and deceleration phases and differences between intake and exhaust strokes due to the non-symmetrical configuration of the machine
One-loop triple collinear splitting amplitudes in QCD
We study the factorisation properties of one-loop scattering amplitudes in the triple collinear limit and extract the universal splitting amplitudes for processes initiated by a gluon. The splitting amplitudes are derived from the analytic Higgs plus four partons amplitudes. We present compact results for primitive helicity splitting amplitudes making use of super-symmetric decompositions. The universality of the collinear factorisation is checked numerically against the full colour six parton squared matrix elements
Toward a better understanding of market potentials for vegan food. A choice experiment for the analysis of breadsticks preferences
4Recently, vegan food has received increased attention from Italian consumers. Despite this fact, it has rarely been the subject of analysis. Our study focuses on consumer preferences for breadsticks in North-Eastern Italy. We applied a choice experiment where a hypothetical market was designed to analyze five characteristics of breadsticks (country of origin, vegan product certification, production method, type of flour, and price). We collected data by interviewing 487 consumers and analyzed them by means of the random parameter logit model. Results suggest that 8% of respondents are willing to pay a premium price for vegan breadsticks and that there is the opportunity to develop local chains for vegan niche markets.openopenMarangon, F.; Tempesta, T.; Troiano, S; Vecchiato, D.Marangon, Francesco; Tempesta, T.; Troiano, Stefania; Vecchiato, D
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