1,721,263 research outputs found
Migration and Trade Flows: New evidence from Spanish Regions
Full text linkWe analyze migrants’ pro-trade effects through a theory-consistent gravity model
augmented with migration variables - both immigration and emigration. We take sub-
national units, i.e. Spanish NUTS3 regions and allow for subnationally heterogeneous
multilateral resistance terms, implying diversified exporting capacity of provinces. We
implement an econometric strategy based on Head and Mayer (2014), which leads us to
selecting the Gamma PML estimator. Comparing the Gamma with OLS estimator we
highlight some shortcomings of previous literature. In particular, language common-
ality is found to magnify the pro-trade effect of immigrants, differently from previous
literature; both emigrants’ and immigrants’ networks are found to exert a positive and
significant pro-trade effect, but in different ways: immigrants affect trade through their
local networks, whereas emigrants affect trade through their national networks
Migration flows and local systems of production: new comparative evidence on Italy and Spain
Full text linkThe thesis explores the question of whether immigrants can spur the internationalization and innovation activities of the local production systems of their countries of destination. It is composed of two parts. In the first part, migrants' pro-trade effects is analysed through a theory-consistent gravity model augmented with migration variables. The analysis takes subnational units, i.e. NUTS3 regions, and compares Italy and Spain. The empirical model allows for subnationally heterogeneous multilateral resistance term. An econometric strategy based on Head and Mayer (2014) is implemented to address the main econometric issues and to select the suitable estimator. This leads to selecting the Gamma PML estimator in the case of Spain and the OLS estimator in the Italian case. The results suggest that applying the same model to different contexts can lead to different results: immigration is found to have a positive trade facilitating effect in the Spanish case and a negative trade-diverting role in the Italian case. This difference is attributed to specificities in the composition and integration patterns of the immigrant population in the two countries; tentative explanations are proposed for the negative effect. The second part of the thesis analyses the determinants of immigrants’ employment focussing, in a comparative perspective, on two case studies of local systems specialized in the mechanic sector, i.e. Reggio Emilia in Italy and Elgoibar in Spain. The two are similar in many respects - income and employment levels, sectoral specialisation, high levels of local social capital - but are marked by quite different capacity of integrating immigrant labour in the core industry. Drawing on the availability of two sets of similar firm-level microdata at the corresponding NUTS2 levels, cluster and discriminant analysis are performed to outline the characteristics of firms hiring immigrants in each context. The comparison of the two regions shows that, in the more inclusive context, immigrants are also much more frequently employed in knowledge-oriented firms. The subjective determinants for hiring immigrants are deepened in a series of semi-structured interviews with the employers. In the local system marked by bridging social capital, immigrants’ employment is found to be determined by a wider set of considerations that span well beyond labour replacement in manual tasks. Diverse work teams are reported to contribute to product development and innovation allowing a combination of cost-saving standardization and cultural-specific customizability to serve foreign tastes
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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Improved magnetic charged system search optimization algorithm with application to satellite formation flying
Full text linkThis paper is devoted to the implementation and application of an improved version of the metaheuristic algorithm called magnetic charged system search. Some modifications and novelties are introduced and tested. Firstly, the authors’ attempt is to develop a self-adaptive and user-friendly algorithm which can automatically set all the preliminary parameters (such as the numbers of particles, the maximum iterations number) and the internal coefficients. Indeed, some mathematical laws are proposed to set the parameters and many coefficients can dynamically change during the optimization process based on the verification of internal conditions. Secondly, some strategies are suggested to enhance the performances of the proposed algorithm. A chaotic local search is introduced to improve the global best particle of each iteration by exploiting the features of ergodicity and randomness. Moreover, a novel technique is proposed to handle bad-defined boundaries; in fact, the possibility to self-enlarge the boundaries of the optimization variables is considered, allowing to achieve the global optimum even if it is located on the boundaries or outside. The algorithm is tested through some benchmark functions and engineering design problems, showing good results, followed by an application regarding the problem of time-suboptimal manoeuvres for satellite formation flying, where the inverse dynamics technique, together with the B-splines, is employed. This analysis proves the ability of the proposed algorithm to optimize control problems related to space engineering, obtaining better results with respect to more common and used algorithms in literature
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