1,563 research outputs found
Predictive Modeling in Post-reform Marketplace
Healthcare reform changes everything. Annual and lifetime dollar limits, underwriting, and preexisting condition exclusion will all be eliminated by 2014. Insurers must offer coverage to any individual regardless of their health status. An overwhelming majority of those who will be mandated to purchase individual insurance is currently uninsured or under-insured. Insurers have insufficient internal data to estimate costs for this new population. A study on how to apply predictive modeling to deal with risks and uncertainties facing healthcare industry in the post-reform marketplace is presented in this article
Phase diagram for morphological transitions of wetting films on chemically structured substrates
Using an interface displacement model we calculate the shapes of thin
liquidlike films adsorbed on flat substrates containing a chemical stripe. We
determine the entire phase diagram of morphological phase transitions in these
films as function of temperature, undersaturation, and stripe widthComment: 15 pages, RevTeX, 7 Figure
Geometry dominated fluid adsorption on sculptured substrates
Experimental methods allow the shape and chemical composition of solid
surfaces to be controlled at a mesoscopic level. Exposing such structured
substrates to a gas close to coexistence with its liquid can produce quite
distinct adsorption characteristics compared to that occuring for planar
systems, which may well play an important role in developing technologies such
as super-repellent surfaces or micro-fluidics. Recent studies have concentrated
on adsorption of liquids at rough and heterogeneous substrates and the
characterisation of nanoscopic liquid films. However, the fundamental effect of
geometry has hardly been addressed. Here we show that varying the shape of the
substrate can exert a profound influence on the adsorption isotherms allowing
us to smoothly connect wetting and capillary condensation through a number of
novel and distinct examples of fluid interfacial phenomena. This opens the
possibility of tailoring the adsorption properties of solid substrates by
sculpturing their surface shape.Comment: 6 pages, 4 figure
Wurtzite Effects on Spin Splitting of GaN/AlN Quantum Wells
A new mechanism (DeltaC1-DeltaC3 coupling) is accounted for the spin
splitting of wurtzite GaN, which is originated from the intrinsic wurtzite
effects (band folding and structure inversion asymmetry). The band-folding
effect generates two conduction bands (DeltaC1 and DeltaC3), in which p-wave
probability has tremendous change when kz approaches anti-crossing zone. The
spin-splitting energy induced by the DeltaC1-DeltaC3 coupling and wurtzite
structure inversion asymmetry is much larger than that evaluated by traditional
Rashba or Dresselhaus effects. When we apply the coupling to GaN/AlN quantum
wells, we find that the spin-splitting energy is sensitively controllable by an
electric field. Based on the mechanism, we proposed a p-wave-enhanced
spin-polarized field effect transistor, made of InxGa1-xN/InyAl1-yN, for
spintronics application.Comment: 12 pages, 4 figures (total 16 pages
The Significance of the -Numerical Range and the Local -Numerical Range in Quantum Control and Quantum Information
This paper shows how C-numerical-range related new strucures may arise from
practical problems in quantum control--and vice versa, how an understanding of
these structures helps to tackle hot topics in quantum information.
We start out with an overview on the role of C-numerical ranges in current
research problems in quantum theory: the quantum mechanical task of maximising
the projection of a point on the unitary orbit of an initial state onto a
target state C relates to the C-numerical radius of A via maximising the trace
function |\tr \{C^\dagger UAU^\dagger\}|. In quantum control of n qubits one
may be interested (i) in having U\in SU(2^n) for the entire dynamics, or (ii)
in restricting the dynamics to {\em local} operations on each qubit, i.e. to
the n-fold tensor product SU(2)\otimes SU(2)\otimes >...\otimes SU(2).
Interestingly, the latter then leads to a novel entity, the {\em local}
C-numerical range W_{\rm loc}(C,A), whose intricate geometry is neither
star-shaped nor simply connected in contrast to the conventional C-numerical
range. This is shown in the accompanying paper (math-ph/0702005).
We present novel applications of the C-numerical range in quantum control
assisted by gradient flows on the local unitary group: (1) they serve as
powerful tools for deciding whether a quantum interaction can be inverted in
time (in a sense generalising Hahn's famous spin echo); (2) they allow for
optimising witnesses of quantum entanglement. We conclude by relating the
relative C-numerical range to problems of constrained quantum optimisation, for
which we also give Lagrange-type gradient flow algorithms.Comment: update relating to math-ph/070200
Templeting of Thin Films Induced by Dewetting on Patterned Surfaces
The instability, dynamics and morphological transitions of patterns in thin
liquid films on periodic striped surfaces (consisting of alternating less and
more wettable stripes) are investigated based on 3-D nonlinear simulations that
account for the inter-site hydrodynamic and surface-energetic interactions. The
film breakup is suppressed on some potentially destabilizing nonwettable sites
when their spacing is below a characteristic lengthscale of the instability,
the upper bound for which is close to the spinodal lengthscale. The thin film
pattern replicates the substrate surface energy pattern closely only when, (a)
the periodicity of substrate pattern matches closely with the characteristic
lengthscale, and (b) the stripe-width is within a range bounded by a lower
critical length, below which no heterogeneous rupture occurs, and an upper
transition length above which complex morphological features bearing little
resemblance to the substrate pattern are formed.Comment: 5 pages TeX (REVTeX 4), other comments: submitted to Phys. Rev.Let
Dewetting of thin films on heterogeneous substrates: Pinning vs. coarsening
We study a model for a thin liquid film dewetting from a periodic
heterogeneous substrate (template). The amplitude and periodicity of a striped
template heterogeneity necessary to obtain a stable periodic stripe pattern,
i.e. pinning, are computed. This requires a stabilization of the longitudinal
and transversal modes driving the typical coarsening dynamics during dewetting
of a thin film on a homogeneous substrate. If the heterogeneity has a larger
spatial period than the critical dewetting mode, weak heterogeneities are
sufficient for pinning. A large region of coexistence between coarsening
dynamics and pinning is found.Comment: 4 pages, 4 figure
Family coordination in families who have a child with autism spectrum disorder
Little is known about the interactions of families where there is a child with autism spectrum disorder (ASD). The present study applies the Lausanne Trilogue Play (LTP) to explore both its applicability to this population as well as to assess resources and areas of deficit in these families. The sample consisted of 68 families with a child with ASD, and 43 families with a typically developing (TD) child. With respect to the global score for family coordination there were several negative correlations: the more severe the symptoms (based on the child’s ADOS score), the more family coordination was dysfunctional. This correlation was particularly high when parents had to play together with the child. In the parts in which only one of the parents played actively with the child, while the other was simply present, some families did achieve scores in the functional range, despite the child’s symptom severity. The outcomes are discussed in terms of their clinical implications both for assessment and for interventio
Anomalous k-dependent spin splitting in wurtzite AlxGa1-xN/GaN heterostructures
We have confirmed the k-dependent spin splitting in wurtzite AlxGa1-xN/GaN
heterostructures. Anomalous beating pattern in Shubnikov-de Haas measurements
arises from the interference of Rashba and Dresselhaus spin-orbit interactions.
The dominant mechanism for the k-dependent spin splitting at high values of k
is attributed to Dresselhaus term which is enhanced by the Delta C1-Delta C3
coupling of wurtzite band folding effect
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