4,944 research outputs found
Documentation of the current fault detection, isolation and reconfiguration software of the AIPS fault-tolerant processor
Documentation is presented of the December 1986 version of the ADA code for the fault detection, isolation, and reconfiguration (FDIR) functions of the Advanced Information processing System (AIPS) Fault-Tolerant Processor (FTP). Because the FTP is still under development and the software is constantly undergoing changes, this should not be considered final documentation of the FDIR software of the FTP
Multiple Charge State Beam Acceleration at Atlas
A test of the acceleration of multiple charge-state uranium beams was
performed at the ATLAS accelerator. A 238U+26 beam was accelerated in the ATLAS
PII linac to 286 MeV (~1.2 MeV/u) and stripped in a carbon foil located 0.5 m
from the entrance of the ATLAS Booster section. A 58Ni9+ 'guide' beam from the
tandem injector was used to tune the Booster for 238U+38. All charge states
from the stripping were injected into the booster and accelerated. Up to 94% of
the beam was accelerated through the Booster linac, with losses mostly in the
lower charge states. The measured beam properties of each charge state and a
comparison to numerical simulations are reported in this paper.Comment: LINAC2000, MOD0
Letter from the Executive Committee of the Alumni Association
Letter concerning copies of a paper and a letter to be distributed at Utah Agricultural College
The Protective Role of Coastal Marshes: A Systematic Review and Meta-analysis
BACKGROUND: Salt marshes lie between many human communities and the coast and have been presumed to protect these communities from coastal hazards by providing important ecosystem services. However, previous characterizations of these ecosystem services have typically been based on a small number of historical studies, and the consistency and extent to which marshes provide these services has not been investigated. Here, we review the current evidence for the specific processes of wave attenuation, shoreline stabilization and floodwater attenuation to determine if and under what conditions salt marshes offer these coastal protection services. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a thorough search and synthesis of the literature with reference to these processes. Seventy-five publications met our selection criteria, and we conducted meta-analyses for publications with sufficient data available for quantitative analysis. We found that combined across all studies (n = 7), salt marsh vegetation had a significant positive effect on wave attenuation as measured by reductions in wave height per unit distance across marsh vegetation. Salt marsh vegetation also had a significant positive effect on shoreline stabilization as measured by accretion, lateral erosion reduction, and marsh surface elevation change (n = 30). Salt marsh characteristics that were positively correlated to both wave attenuation and shoreline stabilization were vegetation density, biomass production, and marsh size. Although we could not find studies quantitatively evaluating floodwater attenuation within salt marshes, there are several studies noting the negative effects of wetland alteration on water quantity regulation within coastal areas. CONCLUSIONS/SIGNIFICANCE: Our results show that salt marshes have value for coastal hazard mitigation and climate change adaptation. Because we do not yet fully understand the magnitude of this value, we propose that decision makers employ natural systems to maximize the benefits and ecosystem services provided by salt marshes and exercise caution when making decisions that erode these services
Getting Real: A Naturalistic Methodology for Using Smartphones to Collect Mediated Communications
This paper contributes an intentionally naturalistic methodology using smartphone logging technology to study communications
in the wild. Smartphone logging can provide tremendous access to communications data from real environments. However,
researchers must consider how it is employed to preserve naturalistic behaviors. Nine considerations are presented to this
end. We also provide a description of a naturalistic logging approach that has been applied successfully to collecting mediated
communications from iPhones. The methodology was designed to intentionally decrease reactivity and resulted in data that were
more accurate than self-reports. Example analyses are also provided to show how data collected can be analyzed to establish
empirical patterns and identify user differences. Smartphone logging technologies offer flexible capabilities to enhance access to
real communications data, but methodologies employing these techniques must be designed appropriately to avoid provoking
naturally occurring behaviors. Functionally, this methodology can be applied to establish empirical patterns and test specific
hypotheses within the field of HCI research. Topically, this methodology can be applied to domains interested in understanding
mediated communications such as mobile content and systems design, teamwork, and social networks
Monoaryl derivatives as transthyretin fibril formation inhibitors: Design, synthesis, biological evaluation and structural analysis
Transthyretin (TTR) is a ß-sheet-rich homotetrameric protein that transports thyroxine (T4) and retinol both in plasma and in cerebrospinal fluid. TTR also interacts with amyloid-β, playing a protective role in Alzheimer's disease. Dissociation of the native transthyretin (TTR) tetramer is widely accepted as the critical step in TTR amyloids fibrillogenesis, and is responsible for extracellular deposition of amyloid fibrils. Small molecules, able to bind in T4 binding sites and stabilize the TTR tetramer, are interesting tools to treat and prevent systemic ATTR amyloidosis. We report here the synthesis, in vitro evaluation and three-dimensional crystallographic analyses of new monoaryl-derivatives in complex with TTR. Of the derivatives reported here, the best inhibitor of TTR fibrillogenesis, 1d, exhibits an activity similar to diflunisal
Effects of Socioeconomic diversity on iPod Touch Device Use in Real-World Environments
Symmetric and asymmetric action integration during cooperative object manipulation in virtual environments
Cooperation between multiple users in a virtual environment (VE) can take place at one of three levels. These
are defined as where users can perceive each other (Level 1), individually change the scene (Level 2), or
simultaneously act on and manipulate the same object (Level 3). Despite representing the highest level of
cooperation, multi-user object manipulation has rarely been studied. This paper describes a behavioral
experiment in which the piano movers' problem (maneuvering a large object through a restricted space) was
used to investigate object manipulation by pairs of participants in a VE. Participants' interactions with the object
were integrated together either symmetrically or asymmetrically. The former only allowed the common
component of participants' actions to take place, but the latter used the mean. Symmetric action integration was
superior for sections of the task when both participants had to perform similar actions, but if participants had to
move in different ways (e.g., one maneuvering themselves through a narrow opening while the other traveled
down a wide corridor) then asymmetric integration was superior. With both forms of integration, the extent to
which participants coordinated their actions was poor and this led to a substantial cooperation overhead (the
reduction in performance caused by having to cooperate with another person)
Three Bosons in One Dimension with Short Range Interactions I: Zero Range Potentials
We consider the three-boson problem with -function interactions in
one spatial dimension. Three different approaches are used to calculate the
phase shifts, which we interpret in the context of the effective range
expansion, for the scattering of one free particle a off of a bound pair. We
first follow a procedure outlined by McGuire in order to obtain an analytic
expression for the desired S-matrix element. This result is then compared to a
variational calculation in the adiabatic hyperspherical representation, and to
a numerical solution to the momentum space Faddeev equations. We find excellent
agreement with the exact phase shifts, and comment on some of the important
features in the scattering and bound-state sectors. In particular, we find that
the 1+2 scattering length is divergent, marking the presence of a zero-energy
resonance which appears as a feature when the pair-wise interactions are
short-range. Finally, we consider the introduction of a three-body interaction,
and comment on the cutoff dependence of the coupling.Comment: 9 figures, 2 table
The Role of Final State Interactions in Quasielastic Fe Reactions at large
A relativistic finite nucleus calculation using a Dirac optical potential is
used to investigate the importance of final state interactions [FSI] at large
momentum transfers in inclusive quasielastic electronuclear reactions. The
optical potential is derived from first-order multiple scattering theory and
then is used to calculate the FSI in a nonspectral Green's function doorway
approach. At intermediate momentum transfers excellent predictions of the
quasielastic Fe experimental data for the longitudinal response
function are obtained. In comparisons with recent measurements at ~GeV/c the theoretical calculations of give good agreement for
the quasielastic peak shape and amplitude, but place the position of the peak
at an energy transfer of about ~MeV higher than the data.Comment: 13 pages typeset using revtex 3.0 with 6 postscript figures in
accompanying uuencoded file; submitted to Phys. Rev.
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