4,306 research outputs found
Dynamical Complexity, Intermittent Turbulence, Coarse-Grained Dissipation, Criticality and Multifractal Processes
The ideas of dynamical complexity induced intermittent turbulence by sporadic
localized interactions of coherent structures are discussed. In particular, we
address the phenomenon of magnetic reconfiguration due to coarse-grained
dissipation as well as the interwoven connection between criticality and
multifractal processes. Specific examples are provided.Comment: 6 pages, 2 figures, submitted to AIP Conference Proceedings for the
6th Annual International Astrophysics Conference, Honolulu, March 16-22, 200
Relativism and universalism in interrogation fairness: a comparative analysis between Europe and China
This paper addresses Chinese interrogation rules from historical and comparative perspectives by relating them to the very different development of interrogation procedure in Europe. A fuller understanding of the evolution of the rules in both contexts is relevant to the present day controversy concerning the universal versus relative nature of interrogation fairness. The comparative analysis reveals that, in fact, the influence of ancient Greek and Chinese civilizations resulted in a great difference between Europe and China regarding legal cultures and institutional arrangements for criminal interrogation procedure. Considering future legal reforms in China, and given the very different historical and institutional context, the likelihood seems low that an ‘autonomous version’ of the right to remain silent and the privilege against self-incrimination will develop on China’s very different soil. However, traditional native resources are also available to legal reformers to ensure a cooperative interviewing style in criminal questioning, and eliminate police-coerced confessions
Pulsar timing in extreme mass ratio binaries: a general relativistic approach
The detection of a pulsar (PSR) in a tight, relativistic orbit around a
supermassive or intermediate mass black hole - such as those in the Galactic
centre or in the centre of Globular clusters - would allow for precision tests
of general relativity (GR) in the strong-field, non-linear regime. We present a
framework for calculating the theoretical time-frequency signal from a PSR in
such an Extreme Mass Ratio Binary (EMRB). This framework is entirely
relativistic with no weak-field approximations and so able to account for all
higher-order strong-field gravitational effects, relativistic spin dynamics,
the convolution with astrophysical effects and the combined impact on the PSR
timing signal. Specifically we calculate both the spacetime path of the pulsar
radio signal and the complex orbital and spin dynamics of a spinning pulsar
around a Kerr black hole, accounting for spacetime curvature and frame
dragging, relativistic and gravitational time delay, gravitational light
bending, temporal and spatial dispersion induced by the presence of plasma
along the line of sight and relativistic aberration. This then allows for a
consistent time-frequency solution to be generated. Such a framework is key for
assessing the use of PSR as probes of strong field GR, helping to inform the
detection of an EMRB system hosting a PSR and, most essentially, for providing
an accurate theoretical basis to then compare with observations to test
fundamental physics.Comment: 19 pages, 15 Figures. Accepted for publication in MNRA
Preferential Acceleration of Coherent Magnetic Structures and Bursty Bulk Flows in Earth's Magnetotail
Observations indicate that the magnetotail convection is turbulent and
bi-modal, consisting of fast bursty bulk flows (BBF) and a nearly stagnant
background. We demonstrate that this observed phenomenon may be understood in
terms of the intermittent interactions, dynamic mergings and preferential
accelerations of coherent magnetic structures under the influence of a
background magnetic field geometry that is consistent with the development of
an X-point mean-field structure.Comment: 12 pages, 5 Postscript figures, uses agums.st
The Green500 List: Escapades to Exascale
Energy efficiency is now a top priority. The first
four years of the Green500 have seen the importance of en-
ergy efficiency in supercomputing grow from an afterthought
to the forefront of innovation as we near a point where sys-
tems will be forced to stop drawing more power. Even so,
the landscape of efficiency in supercomputing continues to
shift, with new trends emerging, and unexpected shifts in
previous predictions.
This paper offers an in-depth analysis of the new and
shifting trends in the Green500. In addition, the analysis of-
fers early indications of the track we are taking toward exas-
cale, and what an exascale machine in 2018 is likely to look
like. Lastly, we discuss the new efforts and collaborations
toward designing and establishing better metrics, method-
ologies and workloads for the measurement and analysis of
energy-efficient supercomputing
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