7,335 research outputs found
Predicting Flood Vulnerable Areas by Using Satellite Remote Sensing Images in Kumamoto City - Japan
Flood is a natural disaster that occurs almost every year in Japan. Based on the flood record, it occurs during the rainy season around July each year. The aim of this research is to predict areas vulnerable to flood. The current research location is the Shiragawa watershed. This study was carried out using DEMs data, ALOS AVNIR-2 and Amedas data to produce watershed area, vegetation index, land cover map and isohyet map. DEM data with spatial resolution of 10 meters was derived from the Geospatial Information Authority of Japan (GSI) in order to show the watershed. The AVNIR-2 imagery was used to create the land cover map and the vegetation index. The land cover map was created by unsupervised method then verified by using land cover map of the Geospatial Information Authority of Japan (GSI). Vegetation index was created by using Normalize Vegetation Index (NDVI) algorithm. The isohyet was obtained using data from rain gauges stationed in Kumamoto Prefecture then interpolating by applying the kriging method. All spatial data was overlaid to create the flood vulnerability map by using Geographic Information System (GIS). This study combines all the data to predict vulnerable areas of flood. The result indicates that the flood occurs in the middle part of Shiragawa watershed
Bi-differential calculus and the KdV equation
A gauged bi-differential calculus over an associative (and not necessarily
commutative) algebra A is an N-graded left A-module with two covariant
derivatives acting on it which, as a consequence of certain (e.g., nonlinear
differential) equations, are flat and anticommute. As a consequence, there is
an iterative construction of generalized conserved currents. We associate a
gauged bi-differential calculus with the Korteweg-de-Vries equation and use it
to compute conserved densities of this equation.Comment: 9 pages, LaTeX, uses amssymb.sty, XXXI Symposium on Mathematical
Physics, Torun, May 1999, replaces "A notion of complete integrability in
noncommutative geometry and the Korteweg-de-Vries equation
CoFeB Thickness Dependence of Thermal Stability Factor in CoFeB/MgO Perpendicular Magnetic Tunnel Junctions
Thermal stability factor (delta) of recording layer was studied in
perpendicular anisotropy CoFeB/MgO magnetic tunnel junctions (p-MTJs) with
various CoFeB recording layer thicknesses and junction sizes. In all series of
p-MTJs with different thicknesses, delta is virtually independent of the
junction sizes of 48-81 nm in diameter. The values of delta increase linearly
with increasing the recording layer thickness. The slope of the linear fit is
explained well by a model based on nucleation type magnetization reversal.Comment: 12 pages, 5 figure
A informação científica no Programa de rádio Prosa Rural.
Este trabalho apresenta a criação e o processo de produção do programa Prosa Rural, da Embrapa, que se destaca como experiência de divulgação científica no meio radiofônico de informações técnico-científicas para o Semi-Árido nordestino e Vale do Jequitinhonha (MG) e regiões Norte, Centro-Oeste e Sudeste do Brasil. O Prosa Rural foi criado pela necessidade da Embrapa em levar a ciência em uma linguagem popularizada para quem tem dificuldade de acesso ao conhecimento ? o produtor rural. As informações técnico-científicas, somadas aos saberes dos produtores rurais, podem dar mais sentido às suas representações sociais e proporcionar melhorias em sua qualidade de vida
On the multispacecraft determination of periodic surface wave phase speeds and wavelengths
Observations of surface waves on the magnetopause indicate a wide range of phase velocities and wavelengths. Their multispacecraft analysis allows a more precise determination of wave characteristics than ever before and reveal shortcomings of approximations to the phase speed that take a predetermined fraction of the magnetosheath speed or the average flow velocity in the boundary layer. We show that time lags between two or more spacecraft can give a qualitative upper estimate, and we confirm the unreliability of flow approximations often used by analyzing a few cases. Using two‐point distant magnetic field observations and spectral analysis of the tailward magnetic field component, we propose an alternative method to estimate the wavelength and phase speed at a single spacecraft from a statistical fit to the data at the other site
Phase diagram at finite temperature and quark density in the strong coupling limit of lattice QCD for color SU(3)
We study the phase diagram of quark matter at finite temperature (T) and
finite chemical potential (mu) in the strong coupling limit of lattice QCD for
color SU(3). We derive an analytical expression of the effective free energy as
a function of T and mu, including baryon effects. The finite temperature
effects are evaluated by integrating over the temporal link variable exactly in
the Polyakov gauge with anti-periodic boundary condition for fermions. The
obtained phase diagram shows the first order phase transition at low
temperatures and the second order phase transition at high temperatures
separated by the tri-critical point in the chiral limit. Baryon has effects to
reduce the effective free energy and to extend the hadron phase to a larger mu
direction at low temperatures.Comment: 18 pages, 10 figure
Classification of Standard Model Particles in Orbifold Grand Unified Theories
We classify the standard model fermions, which originate from bulk fields of
the or representation after orbifold breaking, in
grand unified theories on 5 or 6-dimensional space-time, under the
condition that , and survive as zero modes.Comment: 24 pages, typos corrected, to appear in IJMP
Pulse-coupled resonate-and-fire models
We analyze two pulse-coupled resonate-and-fire neurons. Numerical simulation
reveals that an anti-phase state is an attractor of this model. We can
analytically explain the stability of anti-phase states by means of a return
map of firing times, which we propose in this paper. The resultant stability
condition turns out to be quite simple. The phase diagram based on our theory
shows that there are two types of anti-phase states. One of these cannot be
seen in coupled integrate-and-fire models and is peculiar to resonate-and-fire
models. The results of our theory coincide with those of numerical simulations.Comment: 15 pages, 8 figure
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