56,474 research outputs found
Computationally Tractable Pairwise Complexity Profile
Quantifying the complexity of systems consisting of many interacting parts
has been an important challenge in the field of complex systems in both
abstract and applied contexts. One approach, the complexity profile, is a
measure of the information to describe a system as a function of the scale at
which it is observed. We present a new formulation of the complexity profile,
which expands its possible application to high-dimensional real-world and
mathematically defined systems. The new method is constructed from the pairwise
dependencies between components of the system. The pairwise approach may serve
as both a formulation in its own right and a computationally feasible
approximation to the original complexity profile. We compare it to the original
complexity profile by giving cases where they are equivalent, proving
properties common to both methods, and demonstrating where they differ. Both
formulations satisfy linear superposition for unrelated systems and
conservation of total degrees of freedom (sum rule). The new pairwise
formulation is also a monotonically non-increasing function of scale.
Furthermore, we show that the new formulation defines a class of related
complexity profile functions for a given system, demonstrating the generality
of the formalism.Comment: 18 pages, 3 figure
Two tribunals and an appeal in Seychelles : monitoring and enforcement of legal ethics in a small jurisdiction
On paper, the legal profession in Seychelles does appear to be governed by ethical rules of conduct backed up by appropriate mechanisms for enforcement. However, on closer inspection, it appears that in practice these mechanisms function erratically, if at all. This paper examines the regulatory gap between theory and practice, focusing on recent examples of enforcement actions against lawyers and judges in the jurisdiction. It goes on to discuss possible reasons for this gap, including a lack of ethical education, lack of peer pressure or other incentive to maintain ethical standards, and deficiencies in independence and impartiality of disciplinary tribunals. These reasons are discussed in the context of the small scale of the legal profession in a micro-jurisdiction.peer-reviewe
Multi-hadron-state contamination in nucleon observables from chiral perturbation theory
Multi-particle states with additional pions are expected to be a
non-negligible source of the excited-state contamination in lattice simulations
at the physical point. It is shown that baryon chiral perturbation theory
(ChPT) can be employed to calculate the contamination due to two-particle
nucleon-pion states in various nucleon observables. Results to leading order
are presented for the nucleon axial, tensor and scalar charge and three Mellin
moments of parton distribution functions: the average quark momentum fraction,
the helicity and the transversity moment. Taking into account experimental and
phenomenological results for the charges and moments the impact of the
nucleon-pion-states on lattice estimates for these observables can be
estimated. The nucleon-pion-state contribution leads to an overestimation of
all charges and moments obtained with the plateau method. The overestimation is
at the 5-10% level for source-sink separations of about 2 fm. Existing lattice
data is not in conflict with the ChPT predictions, but the comparison suggests
that significantly larger source-sink separations are needed to compute the
charges and moments with few-percent precision.Comment: 17 pages, 8 figures. Talk given at the 35th International Symposium
on Lattice Field Theory, 18 - 24 June 2017, Granada, Spai
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