4,609 research outputs found
Evaluation of ERTS-1 data for certain hydrological uses
The author has identified the following significant results. ERTS-1 MSS data have been used in a variety of hydrologic research including snow-extent mapping; studies of snowmelt, snowmelt runoff, spectral reflectance of snow for assessing snowpack conditions, and snow albedo; lake ice formation, breakup, and migration; lake current measurements; multispectral studies of lake ice; and flood studies. MSS sensing of soil moisture over a well-vegetated test site was unsuccessfully attempted. Although a powerful research tool, ERTS-1 has very limited use as an operational system for hydrologic communities because of its 18-day revisit cycle and its lack of a quick look capability
Evaluation of LANDSAT-2 data for selected hydrologic applications
There are no author-identified significant results in this report
Evaluation of LANDSAT-2 data for selected hydrologic applications
There are no author-identified significant results in this report
Planets in triple star systems--the case of HD188753
We consider the formation of the recently discovered ``hot Jupiter'' planet
orbiting the primary component of the triple star system HD188753. Although the
current outer orbit of the triple is too tight for a Jupiter-like planet to
have formed and migrated to its current location, the binary may have been much
wider in the past. We assume here that the planetary system formed in an open
star cluster, the dynamical evolution of which subsequently led to changes in
the system's orbital parameters and binary configuration. We calculate cross
sections for various scenarios that could have led to the multiple system
currently observed, and conclude that component A of HD188753 with its planet
were most likely formed in isolation to be swapped in a triple star system by a
dynamical encounter in an open star cluster. We estimate that within 500pc of
the Sun there are about 1200 planetary systems which, like Hd188753, have
orbital parameters unfavorable for forming planets but still having a planet,
making it quite possible that the HD188753 system was indeed formed by a
dynamical encounter in an open star cluster.Comment: ApJ Letters in pres
Cryogenic spectroscopy of ultra-low density colloidal lead chalcogenide quantum dots on chip-scale optical cavities towards single quantum dot near-infrared cavity QED
We present evidence of cavity quantum electrodynamics from a sparse density
of strongly quantum-confined Pb-chalcogenide nanocrystals (between 1 and 10)
approaching single-dot levels on moderately high-Q mesoscopic silicon optical
cavities. Operating at important near-infrared (1500-nm) wavelengths, large
enhancements are observed from devices and strong modifications of the QD
emission are achieved. Saturation spectroscopy of coupled QDs is observed at
77K, highlighting the modified nanocrystal dynamics for quantum information
processing.Comment: * new additional figures and text * 10 pages, 5 figure
Non-Universal Fractional Quantum Hall States in a Quantum wire
The ground state as well as low-lying excitations in a 2D electron system in
strong magnetic fields and a parabolic potential is investigated by the
variational Monte Calro method. Trial wave functions analogous to the Laughlin
state are used with the power-law exponent as the variational parameter. Finite
size scaling of the excitation energy shows that the correlation function at
long distance is characterized by anon-universal exponent in sharp contrast to
the standard Laughlin state.The Laughlin-type state becomes unstable depending
on strength of the confining potential.Comment: 10 pages, REVTE
Preoperative systemic inflammation predicts postoperative infectious complications in patients undergoing curative resection for colorectal cancer
The presence of systemic inflammation before surgery, as evidenced by the glasgow prognostic score (mGPS), predicts poor long-term survival in colorectal cancer. The aim was to examine the relationship between the preoperative mGPS and the development of postoperative complications in patients undergoing potentially curative resection for colorectal cancer. Patients (n=455) who underwent potentially curative resections between 2003 and 2007 were assessed consecutively, and details were recorded in a database. The majority of patients presented for elective surgery (85%) were over the age of 65 years (70%), were male (58%), were deprived (53%), and had TNM stage I/II disease (61%), had preoperative haemoglobin (56%), white cell count (87%) and mGPS 0 (58%) in the normal range. After surgery, 86 (19%) patients developed a postoperative complication; 70 (81%) of which were infectious complications. On multivariate analysis, peritoneal soiling (P<0.01), elevated preoperative white cell count (P<0.05) and mGPS (P<0.01) were independently associated with increased risk of developing a postoperative infection. In elective patients, only the mGPS (OR=1.75, 95% CI=1.17-2.63, P=0.007) was significantly associated with increased risk of developing a postoperative infection. Preoperative elevated mGPS predicts increased postoperative infectious complications in patients undergoing potentially curative resection for colorectal cancer
A simple abstraction of arrays and maps by program translation
We present an approach for the static analysis of programs handling arrays,
with a Galois connection between the semantics of the array program and
semantics of purely scalar operations. The simplest way to implement it is by
automatic, syntactic transformation of the array program into a scalar program
followed analysis of the scalar program with any static analysis technique
(abstract interpretation, acceleration, predicate abstraction,.. .). The
scalars invariants thus obtained are translated back onto the original program
as universally quantified array invariants. We illustrate our approach on a
variety of examples, leading to the " Dutch flag " algorithm
Statistics of lowest excitations in two dimensional Gaussian spin glasses
A detailed investigation of lowest excitations in two-dimensional Gaussian
spin glasses is presented. We show the existence of a new zero-temperature
exponent lambda describing the relative number of finite-volume excitations
with respect to large-scale ones. This exponent yields the standard thermal
exponent of droplet theory theta through the relation, theta=d(lambda-1). Our
work provides a new way to measure the thermal exponent theta without any
assumption about the procedure to generate typical low-lying excitations. We
find clear evidence that theta < theta_{DW} where theta_{DW} is the thermal
exponent obtained in domain-wall theory showing that MacMillan excitations are
not typical.Comment: 4 pages, 3 figures, (v2) revised version, (v3) corrected typo
Finite-Size Scaling of the Domain Wall Entropy Distributions for the 2D Ising Spin Glass
The statistics of domain walls for ground states of the 2D Ising spin glass
with +1 and -1 bonds are studied for square lattices with , and = 0.5, where is the fraction of negative bonds, using periodic
and/or antiperiodic boundary conditions. When is even, almost all domain
walls have energy = 0 or 4. When is odd, most domain walls have
= 2. The probability distribution of the entropy, , is found
to depend strongly on . When , the probability distribution
of is approximately exponential. The variance of this distribution
is proportional to , in agreement with the results of Saul and Kardar. For
the distribution of is not symmetric about zero. In
these cases the variance still appears to be linear in , but the average of
grows faster than . This suggests a one-parameter scaling
form for the -dependence of the distributions of for .Comment: 13 page
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