12,467 research outputs found

    On the fractal properties of cosmic rays and Sun dynamics cross-correlations

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    We investigate the cosmic rays and ten physical parameters of heliosphere behavior considering the scaling features of their temporal evolution. Our analysis start with the cosmic rays measurements by a neutron monitor station located in Moscow, as well sunspot, Ap index, Na/Np, Alfven mach number, DST index, Kp index, Plasma beta (β ), Proton temperature, F10.7 index and Field magnitude |B| (Interplanetary Magnetic Field, IMF), for the period 1976 to early 2020. Each of these datasets was analyzed by using the Multifractal Detrended Fluctuation Analysis and Multifractal Detrended Cross-Correlation Analysis in order to investigate intrinsic properties, like self-similarity and the spectrum of singularities. The main result obtained is that the cosmic rays time series as well the 10 heliospheric parameters exhibit positive long-range correlations with multifractal behavior.APCs y acuerdos transformativos 2022, Springer Natur

    Communication in progressive movement parties: against populism and beyond digitalism

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    In this article, I discuss the conceptualization of movement parties and bridge it with that of communication practices. In particular, I show how the analysis of communication practices within movement parties allows going beyond the technological determinism implicit in concepts such as online populism or digital parties. At different moments in history, social movements entered institutions by forming political parties. When this happened with progressive movements, movement parties were characterized by an appeal to broaden participation through the inclusion of new groups among the population within representative institutions. This general trend is to be kept in mind when addressing the latest wave of movement parties, in particular, the progressive ones, that build upon the history of left-wing party families. Based on these reflections, I critique analyses that, with a specific focus on the core subject of this special issue, have addressed communication strategies, depicting movement parties–including those on the Left–as online populist parties or digital parties. Considering alternative (less technological and more political) explanations, I suggest instead that the effects of the technology are filtered through activists’ agency, the movement parties’ evolution being influenced by movements’ dynamics and competition in the party system. In particular, the concept of communication practices, as developed in social movement studies, will be referred to in order to move beyond some stereotypes coming from either mass media or digital media studies, and so allowing for an historical account of the evolution of movement parties’ communication

    Fast network configuration in Software Defined Networking

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    Software Defined Networking (SDN) provides a framework to dynamically adjust and re-program the data plane with the use of flow rules. The realization of highly adaptive SDNs with the ability to respond to changing demands or recover after a network failure in a short period of time, hinges on efficient updates of flow rules. We model the time to deploy a set of flow rules by the update time at the bottleneck switch, and formulate the problem of selecting paths to minimize the deployment time under feasibility constraints as a mixed integer linear program (MILP). To reduce the computation time of determining flow rules, we propose efficient heuristics designed to approximate the minimum-deployment-time solution by relaxing the MILP or selecting the paths sequentially. Through extensive simulations we show that our algorithms outperform current, shortest path based solutions by reducing the total network configuration time up to 55% while having similar packet loss, in the considered scenarios. We also demonstrate that in a networked environment with a certain fraction of failed links, our algorithms are able to reduce the average time to reestablish disrupted flows by 40%

    A report on SHARP (Spacecraft Health Automated Reasoning Prototype) and the Voyager Neptune encounter

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    The development and application of the Spacecraft Health Automated Reasoning Prototype (SHARP) for the operations of the telecommunications systems and link analysis functions in Voyager mission operations are presented. An overview is provided of the design and functional description of the SHARP system as it was applied to Voyager. Some of the current problems and motivations for automation in real-time mission operations are discussed, as are the specific solutions that SHARP provides. The application of SHARP to Voyager telecommunications had the goal of being a proof-of-capability demonstration of artificial intelligence as applied to the problem of real-time monitoring functions in planetary mission operations. AS part of achieving this central goal, the SHARP application effort was also required to address the issue of the design of an appropriate software system architecture for a ground-based, highly automated spacecraft monitoring system for mission operations, including methods for: (1) embedding a knowledge-based expert system for fault detection, isolation, and recovery within this architecture; (2) acquiring, managing, and fusing the multiple sources of information used by operations personnel; and (3) providing information-rich displays to human operators who need to exercise the capabilities of the automated system. In this regard, SHARP has provided an excellent example of how advanced artificial intelligence techniques can be smoothly integrated with a variety of conventionally programmed software modules, as well as guidance and solutions for many questions about automation in mission operations

    Introduction : solidarities in motion : hybridity and change in migrant support practices

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    The so-called ‘Eurozone’ and ‘migration’ crises mark critical moments in Europe’s recent political history and share similarities to the extent that they both have increased political conflict, mobilised large parts of civil society, and put renewed attention upon the notion of ‘solidarity’. Focusing on the specific case of solidarity with migrants, this articles argues that times of crises have increasingly blurred the lines between contentious and non-contentious forms of civil society engagement. Scrutinising these dynamics of hybridisation, we bridge diverse, yet largely disconnected literatures, including social movement, civil society and humanitarian studies. In particular, we suggest that the disciplinary and analytical distinction between volunteering and non-profit activities on the one hand and social movements and political activism on the other is too rigid and does obscure parts of a complex phenomenon, which is characterised by activities that often intersect between humanitarian practices and contentious politics

    Stratigraphy and petrology of the Miocene MontjuĂŻc delta (Barcelona, Spain)

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    The Neogene rift in the Catalan Coastal Ranges, which is located in the NE part of the Eastern Iberian Margin, corresponds to a system of grabens formed at the north-western edge of the Valencia Trough. In the central part of the Catalan Coastal Ranges are the Vallès - Penedès half-graben in the onshore and the Barcelona half-graben in the offshore, which are separated by the Garraf and the Collserola-Montnegre horsts. Montjuïc hill is a tilted block, which is located to the S of the Barcelona city, between the Collserola-Montnegre horst and the Barcelona half-graben . The Middle Miocene section of Montjuïc is constituted by an alternation of conglomerate, sandstone, mudstone and marlstone beds. The Montjuïc section was divided into four lithostratigraphic units from base to top: (1) The Morrot conglomerate and sandstone Unit, interpreted as delta plain deposits; (2) the Castell conglomerate, sandstone and mudstone Unit considered as proximal delta front deposits; (3) the Miramar marlstone Unit attributed to prodelta deposits; and (4) the Mirador conglomerate, sandstone and mudstone Unit interpreted as delta front deposits. As regards the foraminifera association, the Miocene of Montjuïc may be attributed to the N9-N10 zones of Blow, indicating a Serravallian age. The palaeobotanical record suggests that the climate during the deposition of the Miocene of Montjuïc was temperate-warm and humid. The sandstones and conglomerates are litharenites and lithorudites; they show variable amounts of matrix and are well cemented. The main framework components are quartz, rock fragments and K-feldspar. The Collserola mountain, where Palaeozoic materials crop out is the deduced source area. Montjuïc sandstones are characterized by an early silicic cementation consisting of K-feldspar overgrowths, quartz overgrowths, mesoquartz intergranular cement and a microquartz transformation of a former detrital matrix. A surface cementation is considered for these cements in the absence of compaction and the geological setting

    Inequality and elections in Italy, 1994–2018

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    The increase in income and wealth inequality in Italy is well documented, but less attention has been devoted to its association with social and political outcomes. This article investigates the association between inequality and several variables on socio-economic conditions with the evolution of Italian politics over the 1994–2018 period. Voting in Italy’s regions for the centre-left and centre-right coalitions—with a focus on the Lega—is examined in seven rounds of general elections, before and after the 2008 crisis, which emerges as a key divide in these relationships. The centre-left vote is higher in the regions with an increase in mean wealth and employment rates and shows a reversal after 2008 in the support of part time employees. The centre-right vote is associated with impoverished middle classes and an increase in disparities of Southern regions. The associations shown by Lega voting are distinct from those of other centre-right forces. While political and cultural factors are important to understand political changes, our findings show that a more unequal and distressed society is clearly associated with changes in electoral behaviour
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