9,777 research outputs found
Further rejection of the cybercrime hypothesis
We recently rejected the hypothesis that increases in cybercrime may have caused the international crime drop. Critics subsequently argued that offenders switched from physical crime to cybercrime in recent years, and that lifestyle changes due to ‘leisure IT’ may have caused the international crime drop. Here we explain how the critics misrepresented our argument and do not appear to introduce anything new
Assessing the efficacy of nitrification and urease inhibitors on reducing gaseous N losses in forage seed production of the Saskatchewan parkland region
Non-Peer Reviewe
Data transmission with variable-redundancy error control over a high-frequency channel
Results of computations and field tests on a binary-data-transmission system, operating at 1 kbaud over an h.f. channel, are presented. Error correction is effected by means of error detection and automatic request for repeat, via a feedback channel (a Post Office private line). A set of short, fixed-block-length cyclic codes is available, a code of appropriate redundancy being automatically selected to match the varying channel conditions. The decision about which code to use is made at the receiver, and the transmitter is informed via the feedback channel. The results show that relatively simple, reliable, and efficient data communication can be realised by this means
Surgery groups of the fundamental groups of hyperplane arrangement complements
Using a recent result of Bartels and Lueck (arXiv:0901.0442) we deduce that
the Farrell-Jones Fibered Isomorphism conjecture in L-theory is true for any
group which contains a finite index strongly poly-free normal subgroup, in
particular, for the Artin full braid groups. As a consequence we explicitly
compute the surgery groups of the Artin pure braid groups. This is obtained as
a corollary to a computation of the surgery groups of a more general class of
groups, namely for the fundamental group of the complement of any fiber-type
hyperplane arrangement in the complex n-space.Comment: 11 pages, AMSLATEX file, revised following referee's comments and
suggestions, to appear in Archiv der Mathemati
Evaluation of a closed-path fourier transform infra-red (ftir) multi-component gas analyzer for the simultaneous measurement of nitrous oxide, carbon dioxide and methane
Non-Peer Reviewe
Feasibility study for a Scanning Celestial Attitude Determination System /SCADS/ for three axis attitude determination at a Command and Data Acquisition /CDA/ station Final report
Scanning Celestial Attitude Determination System /SCADS/ for three axis attitude determination at Command and Data Acquisition /CDA/ statio
Impeded Growth of Magnetic Flux Bubbles in the Intermediate State Pattern of Type I Superconductors
Normal state bubble patterns in Type I superconducting Indium and Lead slabs
are studied by the high resolution magneto-optical imaging technique. The size
of bubbles is found to be almost independent of the long-range interaction
between the normal state domains. Under bubble diameter and slab thickness
proper scaling, the results gather onto a single master curve. On this basis,
in the framework of the "current-loop" model [R.E. Goldstein, D.P. Jackson and
A.T. Dorsey, Phys. Rev. Lett. 76, 3818 (1996)], we calculate the equilibrium
diameter of an isolated bubble resulting from the competition between the
Biot-and-Savart interaction of the Meissner current encircling the bubble and
the superconductor-normal interface energy. A good quantitative agreement with
the master curve is found over two decades of the magnetic Bond number. The
isolation of each bubble in the superconducting matrix and the existence of a
positive interface energy are shown to preclude any continuous size variation
of the bubbles after their formation, contrary to the prediction of mean-field
models.Comment: \'{e}quipe Nanostructures Quantique
Discrete Breathers in Klein-Gordon Lattices: a Deflation-Based Approach
Deflation is an efficient numerical technique for identifying new branches of
steady state solutions to nonlinear partial differential equations. Here, we
demonstrate how to extend deflation to discover new periodic orbits in
nonlinear dynamical lattices. We employ our extension to identify discrete
breathers, which are generic exponentially localized, time-periodic solutions
of such lattices. We compare different approaches to using deflation for
periodic orbits, including ones based on a Fourier decomposition of the
solution, as well as ones based on the solution's energy density profile. We
demonstrate the ability of the method to obtain a wide variety of multibreather
solutions without prior knowledge about their spatial profile
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