6,200 research outputs found
Contribution of tonal components to the overall loudness, annoyance and noisiness of noise: Relation between single tones and noise spectral shape
A large scale laboratory investigation of loudness, annoyance, and noisiness produced by single-tone-noise complexes was undertaken to establish a broader data base for quanitification and prediction of perceived annoyance of sounds containing tonal components. Loudness, annoyance, and noisiness were distinguished as separate, distinct, attributes of sound. Three different spectral patterns of broadband noise with and without added tones were studied: broadband-flat, low-pass, and high-pass. Judgments were obtained by absolute magnitude estimation supplement by loudness matching. The data were examined and evaluated to determine the potential effects of (1) the overall sound pressure level (SPL) of the noise-tone complex, (2) tone SPL, (3) noise SPL, (4) tone-to-noise ratio, (5) the frequency of the added tone, (6) noise spectral shape, and (7) subjective attribute judged on absolute magnitude of annoyance. Results showed that, in contrast to noisiness, loudness and annoyance growth behavior depends on the relationship between the frequency of the added tone and the spectral shape of the noise. The close correspondence between the frequency of the added tone and the spectral shape of the noise. The close correspondence between loundness and annoyance suggests that, to better understand perceived annoyance of sound mixtures, it is necessary to relate the results to basic auditory mechanisms governing loudness and masking
Lattice dynamics of anharmonic solids from first principles
An accurate and easily extendable method to deal with lattice dynamics of
solids is offered. It is based on first-principles molecular dynamics
simulations and provides a consistent way to extract the best possible harmonic
- or higher order - potential energy surface at finite temperatures. It is
designed to work even for strongly anharmonic systems where the traditional
quasiharmonic approximation fails. The accuracy and convergence of the method
are controlled in a straightforward way. Excellent agreement of the calculated
phonon dispersion relations at finite temperature with experimental results for
bcc Li and bcc Zr is demonstrated
Comment on "Exposed-Key Weakness of Alpha-Eta" [Phys. Lett. A 370 (2007) 131]
We show that the insecurity claim of the AlphaEta cryptosystem made by C. Ahn
and K. Birnbaum in Phys. Lett. A 370 (2007) 131-135 under heterodyne attack is
based on invalid extrapolations of Shannon's random cipher analysis and on an
invalid statistical independence assumption. We show, both for standard ciphers
and AlphaEta, that expressions of the kind given by Ahn and Birnbaum can at
best be interpreted as security lower bounds.Comment: Published versio
Neuroendocrine bronchial and thymic tumors: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up
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Herbage Production, Nitrogen Fixation and Condensed Tannin Concentrations in \u3cem\u3eLotus glaber\u3c/em\u3e Mill. Germplasm
Lotus glaber (Lg) grows on clay, sandy and medium textured soils in central Chile (32º to 38º S). The diversity of environments where the species grows naturally supports the hypothesis that genetic variability would be found. The objectives of the experiment were to characterise accessions of Lg collected in the region for dry matter (DM) production, comparative capacity to fix atmospheric N and condensed tannins (CT) in Lg grown on clay soils used for cropping rice
Most \u3cem\u3eCaenorhabditis elegans\u3c/em\u3e MicroRNAs are Individually Not Essential for Development or Viability
MicroRNAs (miRNAs), a large class of short noncoding RNAs found in many plants and animals, often act to post-transcriptionally inhibit gene expression. We report the generation of deletion mutations in 87 miRNA genes in Caenorhabditis elegans, expanding the number of mutated miRNA genes to 95, or 83% of known C. elegans miRNAs. We find that the majority of miRNAs are not essential for the viability or development of C. elegans, and mutations in most miRNA genes do not result in grossly abnormal phenotypes. These observations are consistent with the hypothesis that there is significant functional redundancy among miRNAs or among gene pathways regulated by miRNAs. This study represents the first comprehensive genetic analysis of miRNA function in any organism and provides a unique, permanent resource for the systematic study of miRNAs
Atlas Data-Challenge 1 on NorduGrid
The first LHC application ever to be executed in a computational Grid
environment is the so-called ATLAS Data-Challenge 1, more specifically, the
part assigned to the Scandinavian members of the ATLAS Collaboration. Taking
advantage of the NorduGrid testbed and tools, physicists from Denmark, Norway
and Sweden were able to participate in the overall exercise starting in July
2002 and continuing through the rest of 2002 and the first part of 2003 using
solely the NorduGrid environment. This allowed to distribute input data over a
wide area, and rely on the NorduGrid resource discovery mechanism to find an
optimal cluster for job submission. During the whole Data-Challenge 1, more
than 2 TB of input data was processed and more than 2.5 TB of output data was
produced by more than 4750 Grid jobs.Comment: Talk from the 2003 Computing in High Energy Physics and Nuclear
Physics (CHEP03), La Jolla, Ca, USA, March 2003, 7 pages, 3 ps figure
Non-adiabatic Effects in the Dissociation of Oxygen Molecules at the Al(111) Surface
The measured low initial sticking probability of oxygen molecules at the
Al(111) surface that had puzzled the field for many years was recently
explained in a non-adiabatic picture invoking spin-selection rules [J. Behler
et al., Phys. Rev. Lett. 94, 036104 (2005)]. These selection rules tend to
conserve the initial spin-triplet character of the free O2 molecule during the
molecule's approach to the surface. A new locally-constrained
density-functional theory approach gave access to the corresponding
potential-energy surface (PES) seen by such an impinging spin-triplet molecule
and indicated barriers to dissociation which reduce the sticking probability.
Here, we further substantiate this non-adiabatic picture by providing a
detailed account of the employed approach. Building on the previous work, we
focus in particular on inaccuracies in present-day exchange-correlation
functionals. Our analysis shows that small quantitative differences in the
spin-triplet constrained PES obtained with different gradient-corrected
functionals have a noticeable effect on the lowest kinetic energy part of the
resulting sticking curve.Comment: 17 pages including 11 figures; related publications can be found at
http://www.fhi-berlin.mpg.de/th/th.htm
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