47,035 research outputs found
Pionic effects in deep inelastic scattering off nuclei
The structure functions calculated in the Chiral bag model reproduce quite
well, after appropriate perturbative evolution to large energy scales, the
experimental data. We use these results to interpret the structure of the
data as a quenching of the pion decay constant due to the in medium behavior of
the nucleon. This explanation supports recent proposals of this phenomenon
whose origin is the scale invariance of the lagrangian.Comment: 7 pages, figures not included, ftuv92-2
DNALinux Virtual Desktop Edition
The new version of DNALinux (VDE) is presented. DNALinux VDE is a departure from traditional distributions since it uses a virtual machine to bundle together the operating system and bioinformatics applications. The main advantage of this approach is that a virtualized environment doesn't affect a installed system. With a virtual machine a Linux system can be run under a Windows system, provided that the virtual machine player is installed. The included programs are listed and specifications to add more programs are explained. We believe that DNALinux could be used as a standardized virtual machine for learning, using, developing and testing bioinformatics applications
Analysis of the Very Inner Milky Way Dark Matter Distribution and Gamma-Ray Signals
We analyze the possibility that the HESS gamma-ray source at the Galactic
Center could be explained as the secondary flux produced by annihilation of TeV
Dark Matter (TeVDM) particles with locally enhanced density, in a region
spatially compatible with the HESS observations themselves. We study the inner
100 pc considering (i) the extrapolation of several density profiles from
state-of-the-art N-body + Hydrodynamics simulations of Milky Way-like galaxies,
(ii) the DM spike induced by the black hole, and (iii) the DM particles
scattering off by bulge stars. We show that in some cases the DM spike may
provide the enhancement in the flux required to explain the cut-off in the HESS
J1745-290 gamma-ray spectra as TeVDM. In other cases, it may helps to describe
the spatial tail reported by HESS II at angular scales < 0.54 degrees towards
Sgr A.Comment: 6 pages, 3 figures, 1 table. Accepted for publication in Physical
Review D - Rapid Communication
Beyond simulation: designing for uncertainty and robust solutions
Simulation is an increasingly essential tool in the design of our environment, but any model is only as good as the initial assumptions on which it is built. This paper aims to outline some of the limits and potential dangers of reliance on simulation, and suggests how to make our models, and our buildings, more robust with respect to the uncertainty we face in design. It argues that the single analyses provided by most simulations display too precise and too narrow a result to be maximally useful in design, and instead a broader description is required, as might be provided by many differing simulations. Increased computing power now allows this in many areas. Suggestions are made for the further development of simulation tools for design, in that these increased resources should be dedicated not simply to the accuracy of single solutions, but to a bigger picture that takes account of a design’s robustness to change, multiple phenomena that cannot be predicted, and the wider range of possible solutions. Methods for doing so, including statistical methods, adaptive modelling, machine learning and pattern recognition algorithms for identifying persistent structures in models, will be identified. We propose a number of avenues for future research and how these fit into design process, particularly in the case of the design of very large buildings
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