20,791 research outputs found

    Polish grid infrastructure for science and research

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    Structure, functionality, parameters and organization of the computing Grid in Poland is described, mainly from the perspective of high-energy particle physics community, currently its largest consumer and developer. It represents distributed Tier-2 in the worldwide Grid infrastructure. It also provides services and resources for data-intensive applications in other sciences.Comment: Proceeedings of IEEE Eurocon 2007, Warsaw, Poland, 9-12 Sep. 2007, p.44

    Reducing Cascading Failure Risk by Increasing Infrastructure Network Interdependency

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    Increased coupling between critical infrastructure networks, such as power and communication systems, will have important implications for the reliability and security of these systems. To understand the effects of power-communication coupling, several have studied interdependent network models and reported that increased coupling can increase system vulnerability. However, these results come from models that have substantially different mechanisms of cascading, relative to those found in actual power and communication networks. This paper reports on two sets of experiments that compare the network vulnerability implications resulting from simple topological models and models that more accurately capture the dynamics of cascading in power systems. First, we compare a simple model of topological contagion to a model of cascading in power systems and find that the power grid shows a much higher level of vulnerability, relative to the contagion model. Second, we compare a model of topological cascades in coupled networks to three different physics-based models of power grids coupled to communication networks. Again, the more accurate models suggest very different conclusions. In all but the most extreme case, the physics-based power grid models indicate that increased power-communication coupling decreases vulnerability. This is opposite from what one would conclude from the coupled topological model, in which zero coupling is optimal. Finally, an extreme case in which communication failures immediately cause grid failures, suggests that if systems are poorly designed, increased coupling can be harmful. Together these results suggest design strategies for reducing the risk of cascades in interdependent infrastructure systems

    Bayesian inference of spatial and temporal relations in AI patents for EU countries

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    In the paper, we propose two models of Artificial Intelligence (AI) patents in European Union (EU) countries addressing spatial and temporal behaviour. In particular, the models can quantitatively describe the interaction between countries or explain the rapidly growing trends in AI patents. For spatial analysis Poisson regression is used to explain collaboration between a pair of countries measured by the number of common patents. Through Bayesian inference, we estimated the strengths of interactions between countries in the EU and the rest of the world. In particular, a significant lack of cooperation has been identified for some pairs of countries. Alternatively, an inhomogeneous Poisson process combined with the logistic curve growth accurately models the temporal behaviour by an accurate trend line. Bayesian analysis in the time domain revealed an upcoming slowdown in patenting intensity.The research was supported in part by PL-Grid Infrastructure, POWER 2014–2020 program and the Polish Ministry of Science and Higher Education with the subvention funds of the Faculty of Computer Science, Electronics and Telecommunications of AGH University.Peer ReviewedPostprint (published version

    Data Access for LIGO on the OSG

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    During 2015 and 2016, the Laser Interferometer Gravitational-Wave Observatory (LIGO) conducted a three-month observing campaign. These observations delivered the first direct detection of gravitational waves from binary black hole mergers. To search for these signals, the LIGO Scientific Collaboration uses the PyCBC search pipeline. To deliver science results in a timely manner, LIGO collaborated with the Open Science Grid (OSG) to distribute the required computation across a series of dedicated, opportunistic, and allocated resources. To deliver the petabytes necessary for such a large-scale computation, our team deployed a distributed data access infrastructure based on the XRootD server suite and the CernVM File System (CVMFS). This data access strategy grew from simply accessing remote storage to a POSIX-based interface underpinned by distributed, secure caches across the OSG.Comment: 6 pages, 3 figures, submitted to PEARC1

    Tradable Green Certificates as a Policy Instrument? A Discussion on the Case of Poland

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    Quota obligation schemes based on tradable green certificates have become a popular policy instrument to expand power generation from renewable energy sources (RES). Their application, however, can neither be justified as a first-best response to a market failure, nor, in a second-best sense, as an instrument mitigating distortionary effects of the emissions externality, if an emissions trading system exists that fully covers the energy industry. We study how ancillary reasons, in form of overcoming various barriers for RES use and establishing beneficial side-effects, such as industry development, energy security, and abatement of pollutants not covered under the ETS, apply to the scheme recently introduced in Poland. While setting substantial expansion incentives, an advantage for local industry or job-market development or energy security can hardly be seen. With rising power prices for end consumers and awareness that the extra rents from the schemes mostly accrue to foreign investors and renewable and polluting generators, we expect a negative impact on social acceptance for RES and RES deployment support policies.tradable green certificates, environmental policy, Poland, Resource /Energy Economics and Policy,

    Geographic features of zero-emissions urban mobility: the case of electric buses in Europe and Belarus

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    This article reviews the emerging phenomena of electric buses’ deployment in Europe and Belarus within the general framework of the concept of sustainable and electric urban mobility. The author offers a brief overview of electric bus technologies available on the market and a spatial analysis of fleet deployment in Europe. The analysis of the spatial structure of the distribution of e-buses in Europe indicated that, in terms of the number of vehicles in operation, the UK and the Netherlands are the regional leaders, while in terms of the number of cities testing e-buses – Germany, Sweden, and Poland are the leaders. The analysis showed that the main factors supporting the distribution of innovative technology and public support are legislative and regulative framework as well as clear strategic planning and cooperation between local administrations and transportation authorities. Other important aspects, such as network building features, and the location of the charging infrastructure were also discussed. The analysis of the case study of Minsk (the first city to introduce electric buses in Belarus) outlined the typical limiting factors for all types of markets: high battery costs and dependency on infrastructure; recommendations are given to emphasise bus fleet replacement (instead of trolleybus) and to develop a comprehensive sustainable urban mobility strategy
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