12,460 research outputs found
On the fractal properties of cosmic rays and Sun dynamics cross-correlations
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 (ÎČ
), 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
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 partiesâincluding those on the Leftâas 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 activistsâ agency, the movement partiesâ evolution being influenced by movementsâ 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 partiesâ communication
Fast network configuration in Software Defined Networking
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%
Legal determinants of external finance revisited : the inverse relationship between investor protection and societal well-being
This paper investigates relationships between corporate governance traditions and quality of life as measured by a number of widely reported indicators. It provides an empirical analysis of indicators of societal health in developed economies using a classification based on legal traditions. Arguably the most widely cited work in the corporate governance literature has been the collection of papers by La Porta et al. which has shown, inter alia, statistically significant relationships between legal traditions and various proxies for investor protection. We show statistically significant relationships between legal traditions and various proxies for societal health. Our comparative evidence suggests that the interests of investors may not be congruent with the interests of wider society, and that the criteria for judging the effectiveness of approaches to corporate governance should not be restricted to financial metrics
Network recovery from massive failures under uncertain knowledge of damages
This paper addresses progressive network recovery under uncertain knowledge of damages. We formulate the problem as a mixed integer linear programming (MILP), and show that it is NP-Hard. We propose an iterative stochastic recovery algorithm (ISR) to recover the network in a progressive manner to satisfy the critical services. At each optimization step, we make a decision to repair a part of the network and gather more information iteratively, until critical services are completely restored. Three different algorithms are used to find a feasible set and determine which node to repair, namely, 1) an iterative shortest path algorithm (ISR-SRT), 2) an approximate branch and bound (ISR-BB) and 3) an iterative multi-commodity LP relaxation (ISR-MULT). Further, we have modified the state-of-the-Art iterative split and prune (ISP) algorithm to incorporate the uncertain failures. Our results show that ISR-BB and ISR- MULT outperform the state-of-the-Art 'progressive ISP' algorithm while we can configure our choice of trade-off between the execution time, number of repairs (cost) and the demand loss. We show that our recovery algorithm, on average, can reduce the total number of repairs by a factor of about 3 with respect to ISP, while satisfying all critical deman
A report on SHARP (Spacecraft Health Automated Reasoning Prototype) and the Voyager Neptune encounter
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
The so-called âEurozoneâ and âmigrationâ crises mark critical moments in Europeâs 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 âsolidarityâ. 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
Characterization of serine proteinase expression in agaricus bisporus and coprinopsis cinerea by using green fluorescent protein and the A. bisporus SPR1 Promoter
The Agaricus bisporus serine proteinase 1 (SPR1) appears to be significant in both mycelial nutrition and senescence of the fruiting body. We report on the construction of an SPR promoter::green fluorescent protein (GFP) fusion cassette, pGreen_hph1_SPR_GFP, for the investigation of temporal and developmental expression of SPR1 in homobasidiomycetes and to determine how expression is linked to physiological and environmental stimuli. Monitoring of A. bisporus pGreen_hph1_SPR_GFP transformants on media rich in ammonia or containing different nitrogen sources demonstrated that SPR1 is produced in response to available nitrogen. In A. bisporus fruiting bodies, GFP activity was localized to the stipe of postharvest senescing sporophores. pGreen_hph1_SPR_GFP was also transformed into the model basidiomycete Coprinopsis cinerea. Endogenous C. cinerea proteinase activity was profiled during liquid culture and fruiting body development. Maximum activity was observed in the mature cap, while activity dropped during autolysis. Analysis of the C. cinerea genome revealed seven genes showing significant homology to the A. bisporus SPR1 and SPR2 genes. These genes contain the aspartic acid, histidine, and serine residues common to serine proteinases. Analysis of the promoter regions revealed at least one CreA and several AreA regulatory motifs in all sequences. Fruiting was induced in C. cinerea dikaryons, and fluorescence was determined in different developmental stages. GFP expression was observed throughout the life cycle, demonstrating that serine proteinase can be active in all stages of C. cinerea fruiting body development. Serine proteinase expression (GFP fluorescence) was most concentrated during development of young tissue, which may be indicative of high protein turnover during cell differentiatio
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