391,908 research outputs found
âTen strikes and you're outâ: Increasing the number of login attempts can improve password usability
Many users today are struggling to manage an increasing number of passwords. As a consequence, many organizations face an increasing demand on an expensive resource â the system administrators or help desks. This paper suggests that re-considering the â3- strikesâ policy commonly applied to password login systems would be an immediate way of reducing this demand. We analyzed 10 weeks worth of system logs from a sample of 386 users, whose login attempts were not restricted in the usual manner. During that period, only 10% of login attempts failed. We predict that requests for password reminders could be reduced by up to 44% by increasing the number of strikes from 3 to ten
The Doppler Spectra of Medium Grazing Angle Sea Clutter; Part 1: Characterisation
This paper is concerned with the characterisation of Doppler spectra from high range resolution X-band radar sea clutter observed from an airborne platform over the range of grazing angles, 15° to 45°. It is observed that when looking up or down wind there is a strong correlation between mean Doppler shift and local spectrum intensity. When combined with random fluctuations of spectrum width, these characteristics give the spectra a temporal and spatial variability. This behaviour has previously been observed in low grazing angle data and these results confirm the wider applicability of the models developed using that data. The modelling method is also extended here to capture the bimodal behaviour observed with high intensity returns from breaking waves looking up or down-wind
Scaling of nuclear modification factors for hadrons and light nuclei
The number of constituent quarks (NCQ-) scaling of hadrons and the number of
constituent nucleons (NCN-) scaling of light nuclei are proposed for nuclear
modification factors () of hadrons and light nuclei, respectively,
according to the experimental investigations in relativistic heavy-ion
collisions. Based on coalescence mechanism the scalings are performed for pions
and protons in quark level, and light nuclei and He for
nucleonic level, respectively, formed in Au + Au and Pb + Pb collisions and
nice scaling behaviour emerges. NCQ or NCN scaling law of can be
respectively taken as a probe for quark or nucleon coalescence mechanism for
the formation of hadron or light nuclei in relativistic heavy-ion collisions.Comment: 6 pages, 6 figure
Dark Left-Right Model: CDMS, LHC, etc
The Standard Model of particle interactions is extended to include fermion
doublets (n,e)_R transforming under the gauge group SU(2)_R such that n is a
Dirac scotino (dark-matter fermion), with odd R parity. Based on recent CDMS
data, it is shown how this new dark left-right model (DLRM2) favors a Z' gauge
boson at around 1 or 2 TeV and be observable at the LHC. The new W_R gauge
bosons may also contribute significantly to lepton-flavor-changing processes
such as mu to e gamma and mu-e conversion in a nucleus or muonic atom.Comment: 7 pages, 4 figures, typo corrected, talk at Dark Side of Universe
2010, Leon, Mexic
Nearly Mass-Degenerate Majorana Neutrinos: Double Beta Decay and Neutrino Oscillations
Assuming equal tree-level Majorana masses for the standard-model neutrinos,
either from the canonical seesaw mechanism or from a heavy scalar triplet, I
discuss how their radiative splitting may be relevant to neutrinoless double
beta decay and neutrino oscillations.Comment: 12 pages, including 4 figures, talk at NANP9
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