Ranking Electoral Systems through Hierarchical Properties Ranking

Electoral systems are characterized by a wide spectrum of properties that cannot be all satisfied at the same time. We aim at examining such properties within a hierarchical framework, based on Analytic Hierarchy Process, performing pairwise comparisons at various levels of a hierarchy to get a global ranking of the electoral systems. In this way it should be possible to estimate the relative importance of each property with respect to the final ranking of every electoral formula.Electoral systems, global ranking, hierarchy, aggregations

Methods and Models for Environmental Conflicts Analysis and Resolution

This thesis is a description of a particular approach to the analysis and resolution of environmental conflicts. Within this framework we have presented a certain number of models as well as a certain number of methods and procedures with an heavy descriptive value but also with some normative value. On the other hand, this thesis is not a general and exhaustive description of the methods for the analysis and resolution of environmental conflicts nor it contains a full and exhaustive analysis of the literature in this area. Moreover this thesis is not a collection of turnkey recipes that can be used to analyze and resolve a particular environmental problem. An outline of the thesis The present thesis is composed by seven chapters and three short appendices. The first chapter presents the general frameworks of the thesis, defines its motivations and aims, frames some basic concepts and describes both the adopted attitudes and the proposed narratives. The second chapter is devoted essentially to an analysis of the various types of actors and of their interrelations as well as to a presentation of the various perspectives that represent the families of models we discuss in chapters 5 and 6. In the third chapter we provide a detailed critical analysis of System Dynamics as a cognitive tool that acts as a background of the whole thesis though it is mentioned explicitly only in chapter 6. The fourth chapter contains a presentation of two family of protocols (auctions and barters) that we propose both as autonomous tools and as ancillary tools of other protocols. The fifth chapter contains the analysis of the ways through which a coalition of heterogeneous deciders may form in order to define a solution to a common problem. The chapter contains an iterative procedure made of two phases (a static setting phase and a dynamic setting phase) that can be executed repeatedly by the deciders until they reach a satisfactory solution. The sixth chapter contains a description of the procedures and methods through which two or more deciders can enter into competition among themselves on two or more competing projects in order to possibly select one of them and, lastly, share among themselves the costs and benefits associated to the selected project. In the seventh chapter we draw some conclusions, list some open problems and underline some topics worth of further research efforts. The appendices aim at making this thesis as self contained as possible and therefore they contain some of the concepts we refer to in the main chapters but that we preferred to put there so to avoid cluttering too much those chapters. For these reasons we put a brief analysis of some concepts of System Dynamics in Appendix A, a description of some concepts of Decision Theory in Appendix B and a small bunch of concepts of Game Theory in Appendix C

Is technological change really skill biased? Evidence from the introduction of ICTs on the textile sector (1980-2000)

This paper investigates the effects of the introduction of information and communication technologies (ICTs) on the skills of a workforce. Using micro-data collected from workers in the textile sector, we analyse whether the introduction of ICTs has modified workers’ tasks, so that higher skills and longer training periods than before are necessary. Our survey has shown that ICTs i) have replaced unskilled labour in some cases and skilled labour in others; ii) have changed workers’ tasks in some cases but not in others; and finally, iii) have brought about an increase in skills for only a small number of occupations. This empirical evidence does not confirm the hypothesis that technological change, and in particular change introduced by ICTs, is necessarily skill biasedTechnological change, skill bias, textile industry

Revealing infrared populations of nearby galaxies using the Spitzer Space Telescope

Due to their brightness in infrared, asymptotic giant branch (AGB) stars are in important evolutionary stage to be understood at this wavelength. In particular, in next decades, when the infrared optimised telescopes, such as the JWST and the ELT are in operation, it will be essential to include the AGB phase more precisely into the population synthesis models. However, the AGB phase is still one of the remaining major problems in the stellar evolution. This is because the AGB stellar evolution is strongly affected by the mass-loss process from the stars. It is important to describe mass loss more accurately so as to incorporate it into stellar evolutionary models. Recent observations using the Spitzer Space Telescope (SST) enabled us to make a significant progress in understanding the mass loss from AGB stars. Moreover, the SST large surveys contributed to our understanding of the role of AGB stars in chemical enrichment process in galaxies. Here we present the summary of our recent progress.Comment: 4 pages, 2 figures, 1 table; IAU S262 proceeding

The detection of an older population in the Magellanic Bridge

The Magellanic system comprises the Large Magellanic Cloud (LMC), the Small Magellanic Cloud (SMC), and the less frequently observed Magellanic Bridge and Magellanic Stream. The Bridge is traced by neutral gas and has an observed stellar component, while the Stream consists of gas only, with no observed stellar counterpart to date. This study uses catalogues created in the direction of the Bridge from 2MASS and WISE to investigate the stellar content of the Magellanic Bridge. Catalogues were created and colour-magnitude and two colour diagrams were analysed. A study was also carried out on removing the Galactic foreground population in the direction of the Magellanic Bridge, which was an important consideration due to the low stellar density within the Bridge. This study finds that the Magellanic Bridge contains a candidate older stellar population in addition to the younger population already known. The formation of the Magellanic Bridge is likely to have occurred from a tidal event between the LMC and SMC drawing most of the material into it from the SMC. An older population in the Bridge indicates that a stellar content was drawn in during its formation together with a gas component.Comment: 11 pages, 16 figures, accepted by A&A on 17th Jan 201

The metallicity gradient as a tracer of history and structure : the Magellanic Clouds and M33 galaxies

Original article can be found at: http://www.aanda.org/ Copyright The European Southern Observatory (ESO) DOI: 10.1051/0004-6361/200912138Context. The stellar metallicity and its gradient place constraints on the formation and evolution of galaxies. Aims. This is a study of the metallicity gradient of the LMC, SMC and M33 galaxies derived from their asymptotic giant branch (AGB) stars. Methods. The [Fe/H] abundance was derived from the ratio between C- and M-type AGB stars and its variation analysed as a function of galactocentric distance. Galaxy structure parameters were adopted from the literature. Results. The metallicity of the LMC decreases linearly as −0.047±0.003 dex kpc−1 out to ∼8 kpc from the centre. In the SMC, [Fe/H] has a constant value of ∼−1.25 ± 0.01 dex up to ∼12 kpc. The gradient of the M33 disc, until ∼9 kpc, is −0.078 ± 0.003 dex kpc−1 while the outer disc/halo, out to ∼25 kpc, has [Fe/H] ∼ −1.7 dex. Conclusions. The metallicity of the LMC, as traced by different populations, bears the signature of two major star forming episodes: the first one constituting a thick disc/halo population and the second one a thin disc and bar due to a close encounter with the Milky Way and SMC. The [Fe/H] of the recent episode supports an LMC origin for the Stream. The metallicity of the SMC supports star formation, ∼3 Gyr ago, as triggered by LMC interaction and sustained by the bar in the outer region of the galaxy. The SMC [Fe/H] agrees with the present-day abundance in the Bridge and shows no significant gradient. The metallicity of M33 supports an “insideout” disc formation via accretion of metal poor gas from the interstellar medium.Peer reviewe