710 research outputs found

    Political Conflict and Power-sharing in the Origins of Modern Colombia

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    In this paper we present historical evidence and a theoretical analysis of the origins of political stability and instability in Colombia for the period 1850-1950, and their relationship to political, particularly electoral, institutions. We show that the driving force behind institutional change over this period, specifically the move to proportional representation (PR), was the desire of the Conservative and Liberal parties to come up with a way of credibly dividing power to avoid civil war and conflict, a force intensified by the brutal conflict of the War of a Thousand days between 1899 and 1902. The problem with majoritarian electoral institutions was that they did not allocate power in a way which matched the support of the parties in the population, thus encouraging conflict. The strategic advantage of PR was that it avoided such under-representation. The parties however could not initially move to PR because it was not `fraud proof' so instead, in 1905, adopted the "incomplete vote" which simply allocated 2/3 of the legislative seats to the winning party and 1/3 to the loser. This formula brought peace. The switch to PR arose when the Liberals became confident that they could solve problems of fraud. But it only happened because they were able to exploit a division within the Conservatives. The switch also possibly reflected a concern with the rising support for socialism and the desire to divide power more broadly. Our findings shed new light on the origins of electoral systems and the nature of political conflict and its resolution.

    The particularity of emotional words. A grounded approach

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    This work focuses on emotional concepts. We define concepts as patterns of neural activation that re-enact a given external or internal experience, for example the interoceptive experience related to fear. Concepts are mediated and expressed through words. In the following, we will use “words” to refer to word meanings, assuming that words mediate underlying concepts. Since emotional concepts and the words that mediate them are less related to the physical environment than concrete ones, at first sight they might be depicted as abstract concepts. Evidence coming from several studies shows, instead, that the issue is more complex. In this work, we will briefly outline the debate and illustrate results from recent studies on comprehension of concrete, emotional and abstract words in children and adults. We will argue that emotional words can be accounted for from a grounded perspective and will contend that emotional words represent a particular set of words that differs from both the concrete and purely abstract ones

    Exposing implicit biases and stereotypes in human and artificial intelligence: state of the art and challenges with a focus on gender

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    Biases in cognition are ubiquitous. Social psychologists suggested biases and stereotypes serve a multifarious set of cognitive goals, while at the same time stressing their potential harmfulness. Recently, biases and stereotypes became the purview of heated debates in the machine learning community too. Researchers and developers are becoming increasingly aware of the fact that some biases, like gender and race biases, are entrenched in the algorithms some AI applications rely upon. Here, taking into account several existing approaches that address the problem of implicit biases and stereotypes, we propose that a strategy to cope with this phenomenon is to unmask those found in AI systems by understanding their cognitive dimension, rather than simply trying to correct algorithms. To this extent, we present a discussion bridging together findings from cognitive science and insights from machine learning that can be integrated in a state-of-the-art semantic network. Remarkably, this resource can be of assistance to scholars (e.g., cognitive and computer scientists) while at the same time contributing to refine AI regulations affecting social life. We show how only through a thorough understanding of the cognitive processes leading to biases, and through an interdisciplinary effort, we can make the best of AI technology

    Adiabatic Invariants for the FPUT and Toda Chain in the Thermodynamic Limit

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    We consider the Fermi\u2013Pasta\u2013Ulam\u2013Tsingou (FPUT) chain composed by N 6b 1 particles and periodic boundary conditions, and endow the phase space with the Gibbs measure at small temperature \u3b2- 1. Given a fixed 1 64 m 6a N, we prove that the first m integrals of motion of the periodic Toda chain are adiabatic invariants of FPUT (namely they are approximately constant along the Hamiltonian flow of the FPUT) for times of order \u3b2, for initial data in a set of large measure. We also prove that special linear combinations of the harmonic energies are adiabatic invariants of the FPUT on the same time scale, whereas they become adiabatic invariants for all times for the Toda dynamics

    New strategy for the cleaning of paper artworks: A smart combination of gels and biosensors

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    n this work an outlook on the design and application, in the cultural heritage field, of new tools for diagnostic and cleaning use, based on biocompatible hydrogels and electrochemical sensors, is reported. The use of hydrogels is intriguing because it does not require liquid treatment that could induce damage on artworks, while electrochemical biosensors not only are easy to prepare, but also can be selective for a specific compound and therefore are suitable for monitoring the cleaning process. In the field of restoration of paper artworks, more efforts have to be done in order to know how to perform the best way for an effective restoration. Rigid Gellan gel, made up of Gellan gum and calcium acetate, was proposed as a paper cleaning treatment, and selective biosensors for substances to be removed from this gel have been obtained by choosing the appropriate enzymes to be immobilized. Using this approach, it is possible to know when the cleanup process will be completed, avoiding lengthy and sometimes unnecessary cleaning material applications

    Theoretical modeling of UV-Vis absorption and emission spectra in liquid state systems including vibrational and conformational effects: the vertical transition approximation

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    In this paper we describe in detail a general and efficient methodology, based on the perturbed matrix method and molecular dynamics simulations, to model UV-Vis absorption and emission spectra including vibrational and conformational effects. The basic approximation used is to consider all the chromophore atomic coordinates as semiclassical degrees of freedom, hence allowing the calculation of the complete spectral signal by using the electronic vertical transitions as obtained at each possible chromophore configuration, thus including the contributions of vibrations and conformational transitions into the spectrum. As shown for the model system utilized in this paper, solvated 1-phenyl-naphthalene, such an approximation can be rather accurate to reproduce the absorption and emission spectral line shape and properties when, as it often occurs, the vertical vibronic transition largely overlaps the other non-negligible vibronic transitions

    A review of power electronics equipment for all-electric ship MVDC power systems

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    Medium Voltage DC (MVDC) distribution Power Systems for all-electric ships (AES) can be regarded as functionally composed of three subsystems, namely the power sources, the load centers and the distribution network. Extensive use of power electronics is required for connecting power sources and load centers to the MVDC bus and for protecting the MVDC power system through properly placed DC circuit breakers. In this paper, an overview is given of the power electronics equipment found in the literature and on the market that could be suitable for use in future AES MVDC power systems. Some industrial experiences regarding DC generator systems, energy storage apparatus and solid-state DC circuit breaker prototypes are reported in the paper as examples of state-of-the-art realizations. Different DC/DC converters, which can be employed as solid-state transformers, are also discussed and a structure obtained by combining them is proposed

    Mid-sagittal plane detection for advanced physiological measurements in brain scans

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    Objective: The process of diagnosing many neurodegenerative diseases, such as Parkinson's and progressive supranuclear palsy, involves the study of brain magnetic resonance imaging (MRI) scans in order to identify and locate morphological markers that can highlight the health status of the subject. A fundamental step in the pre-processing and analysis of MRI scans is the identification of the mid-sagittal plane, which corresponds to the mid-brain and allows a coordinate reference system for the whole MRI scan set. Approach: To improve the identification of the mid-sagittal plane we have developed an algorithm in Matlab® based on the k-means clustering function. The results have been compared with the evaluation of four experts who manually identified the mid-sagittal plane and whose performances have been combined with a cognitive decisional algorithm in order to define a gold standard. Main results: The comparison provided a mean percentage error of 1.84%. To further refine the automatic procedure we trained a machine learning system using the results from the proposed algorithm and the gold standard. We tested this machine learning system and obtained results comparable to medical raters with a mean absolute error of 1.86 slices. Significance: The system is promising and could be directly incorporated into broader diagnostic support systems

    Versatile hydrogels: An efficient way to clean paper artworks

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    In this work we present innovative materials able to remove in a single, simple and not invasive treatment, different contaminants like starch paste from paper artworks. The materials, based on biocompatible hydrogels, overcome many of the problems usually faced by restorers during the cleaning of paper sample
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