9,832 research outputs found
Consistent forcing scheme in the cascaded lattice Boltzmann method
In this paper, we give a more pellucid derivation for the cascaded lattice
Boltzmann method (CLBM) based on a general multiple-relaxation-time (MRT) frame
through defining a shift matrix. When the shift matrix is a unit matrix, the
CLBM degrades into an MRT LBM. Based on this, a consistent forcing scheme is
developed for the CLBM. The applicability of the non-slip rule, the
second-order convergence rate in space and the property of isotropy for the
consistent forcing scheme is demonstrated through the simulation of several
canonical problems. Several other existing force schemes previously used in the
CLBM are also examined. The study clarifies the relation between MRT LBM and
CLBM under a general framework
Discovery and Testimony of Unretained Experts: Creating a Clear and Equitable Standard to Govern Compliance With Subpoenas
Hearing impairment is known to be one of the most frequent sensory impairments. This condition is known to be a hidden disorder which is under recognised and under treated all around the world. The World Health Organisation (WHO) estimates suggest that there are over 275 million people with hearing impairment and 80% of them living in low and middle income countries. Moreover, the estimates suggest that incidence and prevalence of hearing loss and also the number of people with hearing loss accessing services varies considerably across countries. This rises the need for health promotion (or public awareness campaigns) directed to increase awareness and education of hearing loss and hearing healthcare. This paper provides brief discussion on ‘Stories and storytelling’, ‘Cross-culture and cross-cultural communication’ and ‘Health promotion and cultural sensitivity’. The central focus of this paper is to highlight the applications of storytelling in different cultural context in health promotion, particularly to hearing loss public awareness campaigns
First-principles determined charge and orbital interactions in FeO
The interactions between charge and orbitally ordered -electrons are
important in many transition metal oxides. We propose an effective energy model
for such interactions, parameterized with DFT+U calculations, so that energy
contributions of both electronic and lattice origin can be simultaneously
accounted for. The model is applied to the low-temperature phase of magnetite,
for which we propose a new ground state structure. The effective interactions
on the B-lattice of FeO can be interpreted in terms of electrostatics
and short-range Kugel-Khomskii exchange coupling. The frustration between
optimal charge and orbital orderings leads to a complex energy landscape
whereby the supercell for the charge ordering, orbital ordering and ionic
displacements can all be different.Comment: 15 pages, 4 figure
Yield Enhancement of Digital Microfluidics-Based Biochips Using Space Redundancy and Local Reconfiguration
As microfluidics-based biochips become more complex, manufacturing yield will
have significant influence on production volume and product cost. We propose an
interstitial redundancy approach to enhance the yield of biochips that are
based on droplet-based microfluidics. In this design method, spare cells are
placed in the interstitial sites within the microfluidic array, and they
replace neighboring faulty cells via local reconfiguration. The proposed design
method is evaluated using a set of concurrent real-life bioassays.Comment: Submitted on behalf of EDAA (http://www.edaa.com/
Traffic congestion in interconnected complex networks
Traffic congestion in isolated complex networks has been investigated
extensively over the last decade. Coupled network models have recently been
developed to facilitate further understanding of real complex systems. Analysis
of traffic congestion in coupled complex networks, however, is still relatively
unexplored. In this paper, we try to explore the effect of interconnections on
traffic congestion in interconnected BA scale-free networks. We find that
assortative coupling can alleviate traffic congestion more readily than
disassortative and random coupling when the node processing capacity is
allocated based on node usage probability. Furthermore, the optimal coupling
probability can be found for assortative coupling. However, three types of
coupling preferences achieve similar traffic performance if all nodes share the
same processing capacity. We analyze interconnected Internet AS-level graphs of
South Korea and Japan and obtain similar results. Some practical suggestions
are presented to optimize such real-world interconnected networks accordingly.Comment: 8 page
Modeling incompressible thermal flows using a central-moment-based lattice Boltzmann method
In this paper, a central-moment-based lattice Boltzmann (CLB) method for
incompressible thermal flows is proposed. In the method, the incompressible
Navier-Stokes equations and the convection-diffusion equation for the
temperature field are sloved separately by two different CLB equations. Through
the Chapman-Enskog analysis, the macroscopic governing equations for
incompressible thermal flows can be reproduced. For the flow field, the tedious
implementation for CLB method is simplified by using the shift matrix with a
simplified central-moment set, and the consistent forcing scheme is adopted to
incorporate forcing effects. Compared with several D2Q5
multiple-relaxation-time (MRT) lattice Boltzmann methods for the temperature
equation, the proposed method is shown to be better Galilean invariant through
measuring the thermal diffusivities on a moving reference frame. Thus a higher
Mach number can be used for convection flows, which decreases the computational
load significantly. Numerical simulations for several typical problems confirm
the accuracy, efficiency, and stability of the present method. The grid
convergence tests indicate that the proposed CLB method for incompressible
thermal flows is of second-order accuracy in space
"Black Star" or Astrophysical Black Hole?
Recently wide publicity has been given to a claim by T. Vachaspati that
"black holes do not exist", that the objects known as black holes in
astrophysics should rather be called "black stars" and they not only do not
have event horizons but actually can be the source of spectacular gamma ray
bursts. In this short essay (no flimsier than the original preprint where these
extravagant claims appeared) I demonstrate that these ill-considered claims are
clearly wrong. Yet they present a good occasion to reflect on some well known
but little discussed conceptual difficulties which arise when applying
relativistic terminology in an astrophysical context.Comment: Poster presented at "Compact Objects" meeting in Hunagshan, China,
2-7 July 2007. To be published in the AIP Conference Proceeding serie
Concurrence of arbitrary dimensional bipartite quantum states
We derive an analytical lower bound for the concurrence of a bipartite
quantum state in arbitrary dimension. A functional relation is established
relating concurrence, the Peres-Horodecki criterion and the realignment
criterion. We demonstrate that our bound is exact for some mixed quantum
states. The significance of our method is illustrated by giving a quantitative
evaluation of entanglement for many bound entangled states, some of which fail
to be identified by the usual concurrence estimation method.Comment: 4 pages, published versio
BRST Structures and Symplectic Geometry on a Class of Supermanifolds
By investigating the symplectic geometry and geometric quantization on a
class of supermanifolds, we exhibit BRST structures for a certain kind of
algebras. We discuss the undeformed and q-deformed cases in the classical as
well as in the quantum cases.Comment: 14 pages, Late
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