Analysis and Automatic Processing in Near-field of Eight 1992–1994 Tsunamigenic Earthquakes: Improvements Towards Real-time Tsunami Warning

1995 ◽  
pp. 381-408 ◽  
Author(s):  
F. Schindelé ◽  
D. Reymond ◽  
E. Gaucher ◽  
E. A. Okal
2020 ◽  
Author(s):  
Audrey Gailler ◽  
Daniel Giles

<p>In the framework of operational conditions, the real time coastal modeling in near field is challenging to obtain accurate and reliable tsunami warning products for flooding hazard. Two main approaches are usually developed to generate maps of forecasting inundation and impacts for planning community response. One produces coastal predictions with run-up computation by solving numerically high-resolution forecast models in real time, taking into account all local effects. However, these runs depend on the availability of fine bathymetry/topography grids along the shore and are too time consuming in near field and operational context. The second approach is based on early prediction tools of the coastal wave amplitude calculated from empirical laws or transfer functions derived from these laws. Such tools are suitable in near field context (almost ten times faster than the high-resolution runs), but all local effects are not well taken into account and the assessment of run-up is missing. The linear approximations of coastal tsunami heights are provided very quickly, with global and conservative estimates.</p><p>Within the French Tsunami Warning Center (CENALT), a forecast method based on coastal amplification laws is being implemented. This fast prediction tool provides a coastal tsunami height distribution, calculated from the numerical simulation of the deep ocean tsunami amplitude and using a transfer function derived from the Green’s law. The method involves maps of regionalized values of the empirical correction factor function of the coastal configuration, as a way to amplify or attenuate specific local geometries. Due to a lack of tsunami observations in the NEAM basin, coastal amplification parameters are defined by trial and error regarding high resolution nested grids simulations on the basis of a set of historical and synthetic sources. A method to optimize these local amplification factors by minimizing a cost function is being developed at UCD. Comparisons are shown for several French coastal sites.</p><p>The local tsunami wave heights modeled from the extended Green’s law present a good agreement with the time-consuming high resolution models. The linear approximation is obtained within 1 min and provides estimates within a factor of two in amplitude. Although the resonance effects in harbors and bays are not reproduced and the horizontal inundation calculation needs to be studied further, this method is well suited for an early first estimate of the coastal tsunami threat forecast.</p>


Author(s):  
Christian Luksch ◽  
Lukas Prost ◽  
Michael Wimmer

We present a real-time rendering technique for photometric polygonal lights. Our method uses a numerical integration technique based on a triangulation to calculate noise-free diffuse shading. We include a dynamic point in the triangulation that provides a continuous near-field illumination resembling the shape of the light emitter and its characteristics. We evaluate the accuracy of our approach with a diverse selection of photometric measurement data sets in a comprehensive benchmark framework. Furthermore, we provide an extension for specular reflection on surfaces with arbitrary roughness that facilitates the use of existing real-time shading techniques. Our technique is easy to integrate into real-time rendering systems and extends the range of possible applications with photometric area lights.


2021 ◽  
pp. 073490412199344
Author(s):  
Wolfram Jahn ◽  
Frane Sazunic ◽  
Carlos Sing-Long

Synthesising data from fire scenarios using fire simulations requires iterative running of these simulations. For real-time synthesising, faster-than-real-time simulations are thus necessary. In this article, different model types are assessed according to their complexity to determine the trade-off between the accuracy of the output and the required computing time. A threshold grid size for real-time computational fluid dynamic simulations is identified, and the implications of simplifying existing field fire models by turning off sub-models are assessed. In addition, a temperature correction for two zone models based on the conservation of energy of the hot layer is introduced, to account for spatial variations of temperature in the near field of the fire. The main conclusions are that real-time fire simulations with spatial resolution are possible and that it is not necessary to solve all fine-scale physics to reproduce temperature measurements accurately. There remains, however, a gap in performance between computational fluid dynamic models and zone models that must be explored to achieve faster-than-real-time fire simulations.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1431
Author(s):  
Ilkyu Kim ◽  
Sun-Gyu Lee ◽  
Yong-Hyun Nam ◽  
Jeong-Hae Lee

The development of biomedical devices benefits patients by offering real-time healthcare. In particular, pacemakers have gained a great deal of attention because they offer opportunities for monitoring the patient’s vitals and biological statics in real time. One of the important factors in realizing real-time body-centric sensing is to establish a robust wireless communication link among the medical devices. In this paper, radio transmission and the optimal characteristics for impedance matching the medical telemetry of an implant are investigated. For radio transmission, an integral coupling formula based on 3D vector far-field patterns was firstly applied to compute the antenna coupling between two antennas placed inside and outside of the body. The formula provides the capability for computing the antenna coupling in the near-field and far-field region. In order to include the effects of human implantation, the far-field pattern was characterized taking into account a sphere enclosing an antenna made of human tissue. Furthermore, the characteristics of impedance matching inside the human body were studied by means of inherent wave impedances of electrical and magnetic dipoles. Here, we demonstrate that the implantation of a magnetic dipole is advantageous because it provides similar impedance characteristics to those of the human body.


2002 ◽  
Vol 41 (Part 1, No. 11A) ◽  
pp. 6380-6385
Author(s):  
Hyeong Ryeol Oh ◽  
Dae-Gap Gweon ◽  
Jun-Hee Lee ◽  
Sang-Cheon Kim ◽  
See-Hyung Lee ◽  
...  

2018 ◽  
Vol 53 (12) ◽  
pp. 3599-3612 ◽  
Author(s):  
Philipp Hillger ◽  
Ritesh Jain ◽  
Janusz Grzyb ◽  
Wolfgang Forster ◽  
Bernd Heinemann ◽  
...  

2011 ◽  
Vol 19 (9) ◽  
pp. 8277 ◽  
Author(s):  
F. Blanchard ◽  
A. Doi ◽  
T. Tanaka ◽  
H. Hirori ◽  
H. Tanaka ◽  
...  
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document