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Keeping California cool: Recent cool community developments
In 2006, California introduced the Global Warming Solutions Act (Assembly Bill 32), which requires the state to reduce greenhouse gas emissions to 1990 levels by 2020. "Cool community" strategies, including cool roofs, cool pavements, cool walls and urban vegetation, have been identified as voluntary measures with potential to reduce statewide emissions. In addition, cool community strategies provide co-benefits for residents of California, such as reduced utility bills, improved air quality and enhanced urban livability. To achieve these savings, Lawrence Berkeley National Laboratory (LBNL) has worked with state and local officials, non-profit organizations, school districts, utilities, and manufacturers for 4 years to advance the science and implementation of cool community strategies. This paper summarizes the accomplishments of this program, as well as recent developments in cool community policy in California and other national and international efforts. We also outline lessons learned from these efforts to characterize successful programs and policies to be replicated in the future
Accuracy thresholds of topological color codes on the hexagonal and square-octagonal lattices
Accuracy thresholds of quantum error correcting codes, which exploit
topological properties of systems, defined on two different arrangements of
qubits are predicted. We study the topological color codes on the hexagonal
lattice and on the square-octagonal lattice by the use of mapping into the spin
glass systems. The analysis for the corresponding spin glass systems consists
of the duality, and the gauge symmetry, which has succeeded in deriving
locations of special points, which are deeply related with the accuracy
thresholds of topological error correcting codes. We predict that the accuracy
thresholds for the topological color codes would be for the
hexagonal lattice and for the square-octagonal lattice,
where denotes the error probability on each qubit. Hence both of them are
expected to be slightly lower than the probability for the
quantum Gilbert-Varshamov bound with a zero encoding rate.Comment: 6 pages, 4 figures, the previous title was "Threshold of topological
color code". This is the published version in Phys. Rev.
Solar Orbiter: Exploring the Sun-heliosphere connection
The heliosphere represents a uniquely accessible domain of space, where
fundamental physical processes common to solar, astrophysical and laboratory
plasmas can be studied under conditions impossible to reproduce on Earth and
unfeasible to observe from astronomical distances. Solar Orbiter, the first
mission of ESA's Cosmic Vision 2015-2025 programme, will address the central
question of heliophysics: How does the Sun create and control the heliosphere?
In this paper, we present the scientific goals of the mission and provide an
overview of the mission implementation.Comment: 52 pages, 21 figures, 125 references; accepted for publication in
Solar Physic
Soil Moisture Project Evaluation Workshop
Approaches planned or being developed for measuring and modeling soil moisture parameters are discussed. Topics cover analysis of spatial variability of soil moisture as a function of terrain; the value of soil moisture information in developing stream flow data; energy/scene interactions; applications of satellite data; verifying soil water budget models; soil water profile/soil temperature profile models; soil moisture sensitivity analysis; combinations of the thermal model and microwave; determing planetary roughness and field roughness; how crust or a soil layer effects microwave return; truck radar; and truck/aircraft radar comparison
Error Threshold for Color Codes and Random 3-Body Ising Models
We study the error threshold of color codes, a class of topological quantum
codes that allow a direct implementation of quantum Clifford gates suitable for
entanglement distillation, teleportation and fault-tolerant quantum
computation. We map the error-correction process onto a statistical mechanical
random 3-body Ising model and study its phase diagram via Monte Carlo
simulations. The obtained error threshold of p_c = 0.109(2) is very close to
that of Kitaev's toric code, showing that enhanced computational capabilities
does not necessarily imply lower resistance to noise.Comment: 4 pages, 3 figures, 1 tabl
Monotonic Prefix Consistency in Distributed Systems
We study the issue of data consistency in distributed systems. Specifically,
we consider a distributed system that replicates its data at multiple sites,
which is prone to partitions, and which is assumed to be available (in the
sense that queries are always eventually answered). In such a setting, strong
consistency, where all replicas of the system apply synchronously every
operation, is not possible to implement. However, many weaker consistency
criteria that allow a greater number of behaviors than strong consistency, are
implementable in available distributed systems. We focus on determining the
strongest consistency criterion that can be implemented in a convergent and
available distributed system that tolerates partitions. We focus on objects
where the set of operations can be split into updates and queries. We show that
no criterion stronger than Monotonic Prefix Consistency (MPC) can be
implemented.Comment: Submitted pape
Calibration of the visible and near-infrared channels of the NOAA-9 AVHRR using high-altitude aircraft measurements from August 1985 and October 1986
Visible and near infrared wavelength sensors mounted on operational satellites now in use do not have onboard absolute calibration devices. One means of establishing an in-orbit calibration for a satellite sensor is to make simultaneous measurement of a bright, relatively uniform scene along the satellite view vector from a calibrated instrument on board a high altitude aircraft. Herein, aircraft data were recorded over White Sands, New Mexico at satellite overpass time. Comparison of the coincident aircraft and orbiting satellite data for the visible and near infrared wavelength channels of the NOAA-9 Advanced Very High Resolution Radiometer shows that the calibration of the visible channel was unchanged from prelaunch values, but that the near infrared channel has degraded 6 percent by Aug. 1985. By Oct. 1986 the visible channel had degraded 13 percent and the near infrared channel had degraded 19 percent
Visible and near-infrared channel calibration of the GOES-6 VISSR using high-altitude aircraft measurements
Present and future visible and near-infrared wavelength sensors mounted on operational satellites do not have on-board absolute calibration devices. One means of establishing an in-orbit calibration for a satellite sensor is to make simultaneous measurements of a bright, relatively uniform scene along the satellite view vector from a calibrated instrument on board a high altitude aircraft. Aircraft data were recorded over White Sands, New Mexico, and the coincident aircraft and orbiting satellite data is compared for the visible and near-infrared wavelength channel of the GOES-6 Visible Infrared Spin-Scan Radiometer
Fluctuations in the level density of a Fermi gas
We present a theory that accurately describes the counting of excited states
of a noninteracting fermionic gas. At high excitation energies the results
reproduce Bethe's theory. At low energies oscillatory corrections to the
many--body density of states, related to shell effects, are obtained. The
fluctuations depend non-trivially on energy and particle number. Universality
and connections with Poisson statistics and random matrix theory are
established for regular and chaotic single--particle motion.Comment: 4 pages, 1 figur
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