2,421 research outputs found
Russian gas games or well-oiled conflict? Energy security and the 2014 Ukraine crisis
This essay explores the link between energy security and the 2014 Ukraine crisis. Whenever there is an international conflict involving a major oil or gas producer, commentators are often quick to assume a direct link, and the Ukraine crisis was no exception. Yet, the various avenues through which energy politics have affected the Ukraine crisis, and vice versa, are not well understood. This paper seeks to shed light on the issue by addressing two specific questions. First, how exactly did energy contribute to the crisis in the region? Second, can energy be wielded as a ‘weapon’ by Russia, the EU, or the US? We find that Russian gas pricing played a crucial role as a context factor in igniting the Ukrainian crisis, yet at the same time we guard against ‘energy reductionism’, that is, the fallacy of attributing all events to energy-related issues. We also note that there are strict limits to the so-called energy weapon, whoever employs it. In the conclusion we provide a discussion of the policy implications of these findings
Supersymmetric QCD and noncommutative geometry
We derive supersymmetric quantum chromodynamics from a noncommutative
manifold, using the spectral action principle of Chamseddine and Connes. After
a review of the Einstein-Yang-Mills system in noncommutative geometry, we
establish in full detail that it possesses supersymmetry. This noncommutative
model is then extended to give a theory of quarks, squarks, gluons and gluinos
by constructing a suitable noncommutative spin manifold (i.e. a spectral
triple). The particles are found at their natural place in a spectral triple:
the quarks and gluinos as fermions in the Hilbert space, the gluons and squarks
as bosons as the inner fluctuations of a (generalized) Dirac operator by the
algebra of matrix-valued functions on a manifold. The spectral action principle
applied to this spectral triple gives the Lagrangian of supersymmetric QCD,
including soft supersymmetry breaking mass terms for the squarks. We find that
these results are in good agreement with the physics literature
Improving the robustness of the railway system in Brussels
In order to improve the robustness of a railway system in station areas, this paper introduces an iterative approach to successively solve the route choice problem in station areas to optimality and to improve this solution by applying some changes to the timetable in a tabu search environment. Using a discrete event simulation model, the performance of our algorithms is evaluated based on a case study for the Brussels' area. The railway network of the Brussels' area is introduced and its relevance is emphasized. Computational results indicate an improvement in robustness of about 10%, a decrease in knock-on delay of more than 15%, and a 25% reduction in the number of trains that are confronted with conflicts
Health monitoring of federated future internet experimentation facilities
The federation of Future Internet testbeds as envisaged by the Fed4FIRE project is a complex undertaking. It combines a large number of existing, independent testbeds in a single federation, and presents them to the experimenter as if it were a single infrastructure. Operating and using such an infrastructure requires a profound knowledge of the status of the health of the underlying independent systems. Inspired by network monitoring techniques used to operate the Internet today, this paper considers how a centralized health monitoring system can be set up in a federated environment of Future Internet Experimentation Facilities. We show why it is a vital tool for experimenters and First Level Support in the federation, which health monitoring information must be captured, and how this information can be displayed most appropriately
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