75,046 research outputs found
(Un)Conditional Sample Generation Based on Distribution Element Trees
Recently, distribution element trees (DETs) were introduced as an accurate
and computationally efficient method for density estimation. In this work, we
demonstrate that the DET formulation promotes an easy and inexpensive way to
generate random samples similar to a smooth bootstrap. These samples can be
generated unconditionally, but also, without further complications,
conditionally utilizing available information about certain probability-space
components.Comment: published online in the Journal of Computational and Graphical
Statistic
Hand-tightened, high-pressure seal
To provide flared tubing and hose connections for high-pressure hand tightened cryogenic service, a 1/4-inch male AN seal was modified by machining to receive a special, double-truncated-cone-shaped Kel-F washer between it and the flared flex hose connector
Ferromagnetism in the Periodic Anderson Model: A Comparison of Spectral Density Approximation (SDA), Modified Alloy Analogy (MAA) and Modified Perturbation Theory (MPT)
We compare different approximation schemes for investigating ferromagnetism
in the periodic Anderson model. The use of several approximations allows for a
detailed analysis of the implications of the respective methods, and also of
the mechanisms driving the ferromagnetic transition. For the Kondo limit, our
results confirm a previously proposed mechanism leading to ferromagnetic order,
namely an RKKY exchange mediated via the formation of Kondo screening clouds in
the conduction band. The contrary case is found in the intermediate-valence
regime. Here, the bandshift correction ensuring a correct high-energy expansion
of the self-energy is essential. Inclusion of damping effects reduces stability
of the ferromagnetic phase.Comment: 11 pages, 7 figures, accepted by Eur. Phys. J.
Interim report on the hydrologic features of the Green Swamp area in Central Florida
The Green Swamp area in central Florida is another
area where man is developing agricultural land from marginal
land. Though the area is by no means as extensive as
that of the Everglades, the present efforts for its development
are similar to the early efforts for developing the Everglades
in that many miles of canals and ditches have been
constructed to improve the drainage.
Lest the early mistakes of the Everglades be repeated,
the Florida Department of Water Resources considered that
an appraisal of the physical and hydrologic features of the
area was needed to determine the broad effects of draining
and developing the swamp. This reconnaissance provides information required
by the State of Florida for determining its responsibility
and policy in regard to the Green Swamp area and
for formulating future plans for water management of the
area.
Some of the features that have been determined are:
the amount of rainfall on the area; the pattern of surfacewater
drainage; the amount and direction of surface-water
runoff; the direction of ground-water movement; the interrelationship
of rainfall, surface water, and ground water;
the effects of improved drainage facilities'; and the effects
of the hydrologic environment on the chemical quality of
water of the area.(PDF contains 106 pages.
Phase diagram and dynamic response functions of the Holstein-Hubbard model
We present the phase diagram and dynamical correlation functions for the
Holstein-Hubbard model at half filling and at zero temperature. The
calculations are based on the Dynamical Mean Field Theory. The effective
impurity model is solved using Exact Diagonalization and the Numerical
Renormalization Group. Excluding long-range order, we find three different
paramagnetic phases, metallic, bipolaronic and Mott insulating, depending on
the Hubbard interaction U and the electron-phonon coupling g. We present the
behaviour of the one-electron spectral functions and phonon spectra close to
the metal insulator transitions.Comment: contribution to the SCES04 conferenc
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