1,064 research outputs found

    Citizens, citizenship and European Union: an open bet? The culture of legality

    Get PDF
    Although the meanings of citizenship, active citizenship and organized crime are still open to debate, we try to show the evaluation of the culture of legality and the investments in social, economic and cultural programs for youth as a major defense for such a capillary phenomenon. There is also general agreement that EU programs for endorsing citizenship and active citizenship represent an effective tool for creating transnational networks of young people committed to EU values. Thus, they perceive the culture of legality as the best form of protection against arbitrary violence with references not only to a developed (and eventually harmonized) system of legal sanctions, but also to the fulfillment of individual and collective freedom. We try to shed light on these concept by teh tools provided by political science and philosophy of language

    Effectiveness of Hindman's theorem for bounded sums

    Full text link
    We consider the strength and effective content of restricted versions of Hindman's Theorem in which the number of colors is specified and the length of the sums has a specified finite bound. Let HTkn\mathsf{HT}^{\leq n}_k denote the assertion that for each kk-coloring cc of N\mathbb{N} there is an infinite set XNX \subseteq \mathbb{N} such that all sums xFx\sum_{x \in F} x for FXF \subseteq X and 0<Fn0 < |F| \leq n have the same color. We prove that there is a computable 22-coloring cc of N\mathbb{N} such that there is no infinite computable set XX such that all nonempty sums of at most 22 elements of XX have the same color. It follows that HT22\mathsf{HT}^{\leq 2}_2 is not provable in RCA0\mathsf{RCA}_0 and in fact we show that it implies SRT22\mathsf{SRT}^2_2 in RCA0\mathsf{RCA}_0. We also show that there is a computable instance of HT33\mathsf{HT}^{\leq 3}_3 with all solutions computing 00'. The proof of this result shows that HT33\mathsf{HT}^{\leq 3}_3 implies ACA0\mathsf{ACA}_0 in RCA0\mathsf{RCA}_0

    Complex type 4 structure changing dynamics of digital agents: Nash equilibria of a game with arms race in innovations

    Get PDF
    The new digital economy has renewed interest in how digital agents can innovate. This follows the legacy of John von Neumann dynamical systems theory on complex biological systems as computation. The Gödel-Turing-Post (GTP) logic is shown to be necessary to generate innovation based structure changing Type 4 dynamics of the Wolfram-Chomsky schema. Two syntactic procedures of GTP logic permit digital agents to exit from listable sets of digital technologies to produce novelty and surprises. The first is meta-analyses or offline simulations. The second is a fixed point with a two place encoding of negation or opposition, referred to as the Gödel sentence. It is postulated that in phenomena ranging from the genome to human proteanism, the Gödel sentence is a ubiquitous syntactic construction without which escape from hostile agents qua the Liar is impossible and digital agents become entrained within fixed repertoires. The only recursive best response function of a 2-person adversarial game that can implement strategic innovation in lock-step formation of an arms race is the productive function of the Emil Post [58] set theoretic proof of the Gödel incompleteness result. This overturns the view of game theorists that surprise and innovation cannot be a Nash equilibrium of a game

    Possible polyphase periglaciation and glaciation adjacent to the Moreux impact-crater, Mars

    Get PDF
    International audienceThe cyclicity and temporal succession of glacial-periglacial periods or epochs are keynotes of cold-climate geology on Earth. Relatively recent work within the Mars community has begun to dissect the mid- to higher-latitudinal terrain of Mars for analogical evidence of similar cold-climate cyclicity and succession.Here, we carry on with this work by focusing on the terrain immediately to the north of the Moreux impact-crater (40–44° N, 43–47° E). The crater is located in northern Arabia Terra, to the south of Protonilus Mensae. It lies astride of and postdates Mars' crustal-dichotomy. The latter is a global geological-boundary that separates the ancient southern-highlands from the relatively younger northern-lowland plains.Using cross-cutting relationships, relative stratigraphy and crater-size frequency distributions (CSFDs) we identify three glacial and two periglacial periods that are temporally intertwined and differentiated by a suite of features unique to each of these periods. For example, we report and discuss clusters of pingo-like mounds amidst ridge and trough terrain or “brain terrain”. On Earth, the former are the work of freeze-thaw cycling; on Mars, the latter are thought to be glacial remnants. In turn, the brain terrain is underlain by small-sized polygons possibly formed by thermal contraction cracking and with margins underlain by degraded ice-wedges. Age estimates derived of CSFDs suggest that the polygonised terrain could as much as ~100 Ma, whereas the brain terrain and pingo-like mounds are thought to be ~1–~10 Ma. Possible terminal-moraines that intercept brain-terrain fragments point to an even more recent period of glaciation.If the CSFD age-estimates are valid, then the polygons that underlie the brain terrain and incise the basin floors of our study zone could be an order of magnitude older than most of the age estimates associated with polygonised terrain at other locations on Mars. The fact that there are two distinct periods of polygonization and periglacial activity with a wide offset of time within one relatively small study zone also highlights the extent to which the freeze-thaw cycling of water might be rooted as iteratively and as deeply in Mars' geological history as is its glaciation

    Modelling of the effect of ELMs on fuel retention at the bulk W divertor of JET

    Get PDF
    Effect of ELMs on fuel retention at the bulk W target of JET ITER-Like Wall was studied with multi-scale calculations. Plasma input parameters were taken from ELMy H-mode plasma experiment. The energetic intra-ELM fuel particles get implanted and create near-surface defects up to depths of few tens of nm, which act as the main fuel trapping sites during ELMs. Clustering of implantation-induced vacancies were found to take place. The incoming flux of inter-ELM plasma particles increases the different filling levels of trapped fuel in defects. The temperature increase of the W target during the pulse increases the fuel detrapping rate. The inter-ELM fuel particle flux refills the partially emptied trapping sites and fills new sites. This leads to a competing effect on the retention and release rates of the implanted particles. At high temperatures the main retention appeared in larger vacancy clusters due to increased clustering rate

    On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

    Get PDF
    A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

    Numerical and experimental analysis of wrinkling during the cup drawing of an AA5042 aluminium alloy

    Get PDF
    The recent trend to reduce the thickness of metallic sheets used in forming processes strongly increases the likelihood of the occurrence of wrinkling. Thus, in order to obtain defect-free components, the prediction of this kind of defect becomes extremely important in the tool design and selection of process parameters. In this study, the sheet metal forming process proposed as a benchmark in the Numisheet 2014 conference is selected to analyse the influence of the tool geometry on wrinkling behaviour, as well as the reliability of the developed numerical model. The side-wall wrinkling during the deep drawing process of a cylindrical cup in AA5042 aluminium alloy is investigated through finite element simulation and experimental measurements. The material plastic anisotropy is modelled with an advanced yield criterion beyond the isotropic (von Mises) material behaviour. The results show that the shape of the wrinkles predicted by the numerical model is strongly affected by the finite element mesh used in the blank discretization. The accurate modelling of the plastic anisotropy of the aluminium alloy yields numerical results that are in good agreement with the experiments, particularly the shape and location of the wrinkles. The predicted punch force evolution is strongly influenced by the friction coefficient used in the model. Moreover, the two punch geometries provide drawn cups with different wrinkle waves, mainly differing in amplitude.The authors gratefully acknowledge the financial support of the Portuguese Foundation for Science and Technology (FCT) under project PTDC/EMS-TEC/1805/2012. The first author is also grateful to the FCT for the Postdoctoral grant SFRH/BPD/101334/2014 and P.D. Barros is grateful to the FCT for the PhD Grant SFRH/BD/98545/2013info:eu-repo/semantics/publishedVersio
    corecore