38,627 research outputs found
Multifractal and Network Analysis of Phase Transition
Many models and real complex systems possess critical thresholds at which the
systems shift from one sate to another. The discovery of the early warnings of
the systems in the vicinity of critical point are of great importance to
estimate how far a system is from a critical threshold. Multifractal Detrended
Fluctuation analysis (MF-DFA) and visibility graph method have been employed to
investigate the fluctuation and geometrical structures of magnetization time
series of two-dimensional Ising model around critical point. The Hurst exponent
has been confirmed to be a good indicator of phase transition. Increase of the
multifractality of the time series have been observed from generalized Hurst
exponents and singularity spectrum. Both Long-term correlation and broad
probability density function are identified to be the sources of
multifractality of time series near critical regime. Heterogeneous nature of
the networks constructed from magnetization time series have validated the
fractal properties of magnetization time series from complex network
perspective. Evolution of the topology quantities such as clustering
coefficient, average degree, average shortest path length, density,
assortativity and heterogeneity serve as early warnings of phase transition.
Those methods and results can provide new insights about analysis of phase
transition problems and can be used as early warnings for various complex
systems.Comment: 23 pages, 11 figure
Cockpit display of hazardous wind shear information
Information on cockpit display of wind shear information is given in viewgraph form. Based on the current status of windshear sensors and candidate data dissemination systems, the near-term capabilities for windshear avoidance will most likely include: (1) Ground-based detection: TDWR (Terminal Doppler Weather Radar), LLWAS (Low-Level Windshear Alert System), Automated PIREPS; (2) Ground-Air datalinks: Air traffic control voice channels, Mode-S digital datalink, ACARS alphanumeric datalink. The possible datapaths for integration of these systems are illustrated in a diagram. In the future, airborne windshear detection systems such as lidars, passive IR detectors, or airborne Doppler radars may also become available. Possible future datalinks include satellite downlink and specialized en route weather channels
Improving the Effectiveness of the Dissemination Method in Disaster Early Warning Messages
The dissemination of disaster early warning messages has a significant role
in the effectiveness and serviceability in an Early Warning System (EWS). Providing
the community in a disaster area with an adequate dissemination and communication
of early warning messages will improve people's awareness and reaction to a natural
hazard. People who live in a disaster area play a crucial role in the success of EWS.
Malaysian, Sri Lankan, Bangladeshi and Indonesian authorities employ mobile phone
applications, such as text messages (SMS), as a tool for disaster warning messages.
However, there are many challenges in methods for disseminating early warning
messages. One of the challenges is the dissemination method in which only
notification messages are sent. In this paper, we propose confirmation or verification
messages, as part of disaster early warning messages, by using text messages.
Confirmation messages are messages that use a verification channel to provide up-to-
date official information about the latest natural disaster conditions.
Keywords: disaster management, early warning messages dissemination, SM
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