1,921 research outputs found
Apparatus and method for improvised explosive device (IED) network analysis
PatentTools and apparatus are presented for identification and
analysis of improvised explosive device (IED) networks,
including data acquisition tools and techniques providing
structured prompting and predefined answers for acquiring
structured IED data reports in a streamlined fashion using
uniform terminology with respect to IED components and/or
structure, as well as analysis methodologies employing IED
component level analysis with adjustable similarity correlation
and IED attribute filtering to expeditiously identify
likely IED networks using graphical renderings of IED
locations in a given geolocation range of interest and connection
indicators
A Simplest Swimmer at Low Reynolds Number: Three Linked Spheres
We propose a very simple one-dimensional swimmer consisting of three spheres
that are linked by rigid rods whose lengths can change between two values. With
a periodic motion in a non-reciprocal fashion, which breaks the time-reversal
symmetry as well as the translational symmetry, we show that the model device
can swim at low Reynolds number. This model system could be used in
constructing molecular-size machines
Downsizing: Is There a "Right" Way?
In response to the pressures of surviving in in a competitive global market, many companies are turning to downsizing, right sizing, restructuring, reduction-in-force, and/or business process re-engineering, among others. Regardless of the terminology used, an inevitable result is a loss of jobs. Companies fail to grasp the profound ramifications of downsizing for both the people laid off and the organization and work force that remain after downsizing is complete. A search of the literature was conducted to ascertain what leading theorists and practitioners are saying about downsizing and the "right" way to go about it. This search culminated in the Nine Point Model for Downsizing (NPMD). The model is used to analyze a downsizing case study involving the December 1997 layoff of 19.000 employees by a leading manufacturer of imagine products
Universal dynamical decoupling of a single solid-state spin from a spin bath
Controlling the interaction of a single quantum system with its environment
is a fundamental challenge in quantum science and technology. We dramatically
suppress the coupling of a single spin in diamond with the surrounding spin
bath by using double-axis dynamical decoupling. The coherence is preserved for
arbitrary quantum states, as verified by quantum process tomography. The
resulting coherence time enhancement is found to follow a general scaling with
the number of decoupling pulses. No limit is observed for the decoupling action
up to 136 pulses, for which the coherence time is enhanced more than 25 times
compared to spin echo. These results uncover a new regime for experimental
quantum science and allow to overcome a major hurdle for implementing quantum
information protocols.Comment: submitted 24 May 2010; published online 9 September 201
Microscale swimming: The molecular dynamics approach
The self-propelled motion of microscopic bodies immersed in a fluid medium is
studied using molecular dynamics simulation. The advantage of the atomistic
approach is that the detailed level of description allows complete freedom in
specifying the swimmer design and its coupling with the surrounding fluid. A
series of two-dimensional swimming bodies employing a variety of propulsion
mechanisms -- motivated by biological and microrobotic designs -- is
investigated, including the use of moving limbs, changing body shapes and fluid
jets. The swimming efficiency and the nature of the induced, time-dependent
flow fields are found to differ widely among body designs and propulsion
mechanisms.Comment: 5 pages, 3 figures (minor changes to text
PyWiFeS: a rapid data reduction pipeline for the Wide Field Spectrograph (WiFeS)
We present PyWiFeS, a new Python-based data reduction pipeline for the Wide Field Spectrograph (WiFeS). PyWiFeS consists of a series of core data processing routines built on standard scientific Python packages commonly used in astronomical applications. Included in PyWiFeS is an implementation of a new global optical model of the spectrograph which provides wavelengths solutions accurate to ?0.05 Ã… (RMS) across the entire detector. The core PyWiFeS package is designed to be scriptable to enable batch processing of large quantities of data, and we present a default format for handling of observation metadata and scripting of data reduction
Measurement of Gilbert damping parameters in nanoscale CPP-GMR spin-valves
In-situ, device level measurement of thermal mag-noise spectral linewidths in
60nm diameter CPP-GMR spin-valve stacks of IrMn/ref/Cu/free, with reference and
free layer of similar CoFe/CoFeGe alloy, are used to simultaneously determine
the intrinsic Gilbert damping for both magnetic layers. It is shown that
careful alignment at a "magic-angle" between free and reference layer static
equilibrium magnetization can allow direct measurement of the broadband
intrinsic thermal spectra in the virtual absence of spin-torque effects which
otherwise grossly distort the spectral line shapes and require linewidth
extrapolations to zero current (which are nonetheless also shown to agree well
with the direct method). The experimental magic-angle spectra are shown to be
in good qualitative and quantitative agreement with both macrospin calculations
and micromagnetic eigenmode analysis. Despite similar composition and
thickness, it is repeatedly found that the IrMn exchange pinned reference layer
has ten times larger intrinsic Gilbert damping (alpha ~ 0.1) than that of the
free-layer (alpha ~ 0.01). It is argued that the large reference layer damping
results from strong, off -resonant coupling to to lossy modes of an IrMn/ref
couple, rather than commonly invoked two-magnon processes.Comment: 11 pages (2-column format), 12 figures. This work was presented at
the 2010 Joint MMM-Intermag Conference (Washington, DC) as paper AB-01
(invited
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