800 research outputs found
Mapping analysis and planning system for the John F. Kennedy Space Center
Environmental management, impact assessment, research and monitoring are multidisciplinary activities which are ideally suited to incorporate a multi-media approach to environmental problem solving. Geographic information systems (GIS), simulation models, neural networks and expert-system software are some of the advancing technologies being used for data management, query, analysis and display. At the 140,000 acre John F. Kennedy Space Center, the Advanced Software Technology group has been supporting development and implementation of a program that integrates these and other rapidly evolving hardware and software capabilities into a comprehensive Mapping, Analysis and Planning System (MAPS) based in a workstation/local are network environment. An expert-system shell is being developed to link the various databases to guide users through the numerous stages of a facility siting and environmental assessment. The expert-system shell approach is appealing for its ease of data access by management-level decision makers while maintaining the involvement of the data specialists. This, as well as increased efficiency and accuracy in data analysis and report preparation, can benefit any organization involved in natural resources management
Effective one-dimensionality of AC hopping conduction in the extreme disorder limit
It is argued that in the limit of extreme disorder AC hopping is dominated by
"percolation paths". Modelling a percolation path as a one-dimensional path
with a sharp jump rate cut-off leads to an expression for the universal AC
conductivity, that fits computer simulations in two and three dimensions better
than the effective medium approximation.Comment: 6 postscript figure
Differential electrophysiological response during rest, self-referential, and non-self-referential tasks in human posteromedial cortex
The electrophysiological basis for higher brain activity during rest and internally directed cognition within the human default mode network
(DMN) remains largely unknown. Here we use intracranial recordings in
the human posteromedial cortex (PMC), a core node within the DMN,
during conditions of cued rest, autobiographical judgments, and
arithmetic processing. We found a heterogeneous profile of PMC
responses in functional, spatial, and temporal domains. Although the
majority of PMC sites showed increased broad gamma band activity
(30-180 Hz) during rest, some PMC sites, proximal to the retrosplenial
cortex, responded selectively to autobiographical stimuli. However, no
site responded to both conditions, even though they were located within
the boundaries of the DMN identified with resting-state functional
imaging and similarly deactivated during arithmetic processing. These
findings, which provide electrophysiological evidence for heterogeneity
within the core of the DMN, will have important implications for
neuroimaging studies of the DMN
Harmonic Vibrational Excitations in Disordered Solids and the "Boson Peak"
We consider a system of coupled classical harmonic oscillators with spatially
fluctuating nearest-neighbor force constants on a simple cubic lattice. The
model is solved both by numerically diagonalizing the Hamiltonian and by
applying the single-bond coherent potential approximation. The results for the
density of states are in excellent agreement with each other. As
the degree of disorder is increased the system becomes unstable due to the
presence of negative force constants. If the system is near the borderline of
stability a low-frequency peak appears in the reduced density of states
as a precursor of the instability. We argue that this peak
is the analogon of the "boson peak", observed in structural glasses. By means
of the level distance statistics we show that the peak is not associated with
localized states
Edging your bets: advantage play, gambling, crime and victimisation
Consumerism, industrial development and regulatory liberalisation have underpinned the ascendance of gambling to a mainstream consumption practice. In particular, the online gambling environment has been marketed as a site of ‘safe risks’ where citizens can engage in a multitude of different forms of aleatory consumption. This paper offers a virtual ethnography of an online ‘advantage play’ subculture. It demonstrates how advantage players have reinterpreted the online gambling landscape as an environment saturated with crime and victimisation. In this virtual world, advantage play is no longer simply an instrumental act concerned with profit accumulation to finance consumer desires. Rather, it acts as an opportunity for individuals to engage in a unique form of edgework, whereby the threat to one’s well-being is tested through an ability to avoid crime and victimisation. This paper demonstrates how mediated environments may act as sites for edgeworking and how the potential for victimisation can be something that is actively engaged with
Erratum: Author Correction: System immunology-based identification of blood transcriptional modules correlating to antibody responses in sheep.
[This corrects the article DOI: 10.1038/s41541-018-0078-0.]
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