@MastersThesis{Muralikrishna:2009:PrÍnGe,
author = "Muralikrishna, Amita",
title = "Previs{\~a}o do {\'{\i}}ndice geomagn{\'e}tico dst utilizando
redes neurais artificiais e {\'a}rvore de decis{\~a}o",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2009",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2009-02-13",
keywords = "Redes neurais artificiais, clima espacial, DST, tempestade
magn{\'e}tica, {\'a}rvore de decis{\~a}o, perceptron
m{\'u}ltiplas camadas, backpropagation, artificial neural
networks, space weather, magnetic storm, decision tree, multilayer
perceptron.",
abstract = "A Terra sofre constante influ{\^e}ncia da atividade solar
atrav{\'e}s do vento solar, que traz consigo estruturas
resultantes, principalmente, de eventos solares como
explos{\~o}es solares e eje{\c{c}}{\~o}es coronais de massa. A
intera{\c{c}}{\~a}o quase est{\'a}tica do vento solar com o
campo geomagn{\'e}tico forma a estrutura denominada magnetosfera,
que funciona como um escudo, que protege o planeta do plasma
provindo do Sol. No entanto, em fun{\c{c}}{\~a}o das
caracter{\'{\i}}sticas que as estruturas de origem solar
adquirem ao longo do meio interplanet{\'a}rio, pode haver
penetra{\c{c}}{\~a}o de parte dessa mat{\'e}ria para dentro da
magnetosfera. Como conseq{\"u}{\^e}ncia, diversos tipos de
dist{\'u}rbios podem ser gerados no planeta, como, por exemplo,
as auroras e as tempestades geomagn{\'e}ticas, as quais podem
ocasionar diversos danos aos sistemas tecnol{\'o}gicos, entre
outros preju{\'{\i}}zos. Este trabalho aborda a
rela{\c{c}}{\~a}o entre as caracter{\'{\i}}sticas do meio
interplanet{\'a}rio durante o avan{\c{c}}o de estruturas
interplanet{\'a}rias em dire{\c{c}}{\~a}o {\`a} Terra e os
efeitos sentidos pelo campo geomagn{\'e}tico, como resposta a
essas caracter{\'{\i}}sticas. O foco principal {\'e} a
previs{\~a}o do comportamento do campo geomagn{\'e}tico, medido,
neste trabalho, pelo {\'{\i}}ndice geomagn{\'e}tico Dst,
levando-se em conta, principalmente, as tr{\^e}s coordenadas do
campo magn{\'e}tico interplanet{\'a}rio. As ferramentas
escolhidas para resolver o problema n{\~a}o-linear foram as
t{\'e}cnicas: Rede Neural Artificial do tipo Perceptron de
M{\'u}ltiplas Camadas, treinada com algoritmo backpropagation,
Mapa Auto-organiz{\'a}vel de Kohonen e {\'A}rvore de
Decis{\~a}o com algoritmo J48. Foi poss{\'{\i}}vel comprovar
algumas rela{\c{c}}{\~o}es e questionar a exist{\^e}ncia de
outras com a {\'A}rvore de Decis{\~a}o e prever, com {\'o}timo
percentual de efici{\^e}ncia, o {\'{\i}}ndice geomagn{\'e}tico
Dst com a Rede MLP. ABSTRACT: The Earth suffers constant influence
of the solar activity through the solar wind, which brings with it
the resulting structures, mainly phenomena like solar flares and
coronal mass ejection. The almost static interaction between the
solar wind and the geomagnetic field forms a structure called
magnetosphere, which acts as a shield that protects the planet
from radiation and solar plasma. However, depending on the
characteristics that these structures of solar origin acquire
throughout the interplanetary medium, a part of the energy and
matter may penetrate into the magnetosphere. As a result,
different types of disturbances can be generated on the planet,
for example, the aurora and the geomagnetic storms, which can
cause damage to various technological systems, among other losses.
The present work formulates the relationship between the
characteristics of the interplanetary medium during the progress
of the interplanetary structures towards the Earth and the effects
observed on the geomagnetic field, in response to these
characteristics. The main focus is on forecasting the behavior of
the geomagnetic field, represented in this work by the Dst index,
using for that, mainly, the three interplanetary magnetic field
components. The tools chosen here to solve the non-linear problem
were the Multi-layer Perceptrons Artificial Neural Network,
trained with the backpropagation algorithm; the Kohonen
Self-Organizing Map and the Decision Tree with the J48 algorithm.
It was possible to establish some relationships and to question
the existence of others with the Decision Tree, and predict the
geomagnetic Dst index with great percentage efficiency with the
Artificial Neural Network.",
committee = "Rosa, Reinaldo Roberto (presidente) and Silva, Jos{\'e}
Dem{\'{\i}}sio Sim{\~o}es da (orientador) and Lago, Alisson Dal
(orientador) and Alarcon, Walter Demetrio Gonzalez and
Os{\'o}rio, Fernando Santos",
copyholder = "SID/SCD",
englishtitle = "Geomagnetic DST index forecast using artificial neural networks
and decision tree",
language = "pt",
pages = "132",
ibi = "8JMKD3MGP8W/355JR6S",
url = "http://urlib.net/rep/8JMKD3MGP8W/355JR6S",
targetfile = "publicacao.pdf",
urlaccessdate = "26 fev. 2021"
}