@PhDThesis{CerejaJúnior:2018:FrAdDi,
author = "Cereja J{\'u}nior, Moacyr Gon{\c{c}}alves",
title = "Um framework para adapta{\c{c}}{\~a}o din{\^a}mica de software
aplicado a sistemas de segmento solo",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2018",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2018-05-04",
keywords = "sistemas auto-adapt{\'a}veis, sistemas solo,
computa{\c{c}}{\~a}o aut{\^o}noma, arquiteturas de software,
qualidade de servi{\c{c}}o, self-adaptive systems, space ground
systems, autonomic computing, software architecture, quality of
service (QoS).",
abstract = "Arquiteturas de sistemas espaciais s{\~a}o compostas de tr{\^e}s
segmentos: espacial, lan{\c{c}}ador e solo. Nos {\'u}ltimos
anos, com refer{\^e}ncia ao segmento espacial,
inova{\c{c}}{\~o}es tecnol{\'o}gicas, como cubesats, t{\^e}m
produzido impactos como a diminui{\c{c}}{\~a}o do tamanho dos
sat{\'e}lites e aumento do volume de objetos no espa{\c{c}}o.
Desta forma, ao inv{\'e}s de adotar grandes sat{\'e}lites nas
miss{\~o}es espaciais, s{\~a}o utilizados
constela{\c{c}}{\~o}es e mega constela{\c{c}}{\~o}es. Esta
altera{\c{c}}{\~a}o arquitetural produz um n{\'u}mero grande de
sat{\'e}lites que devem ser controlados de forma simult{\^a}nea
e o aumento da volumetria de dados que devem ser processados pelos
sistemas de segmento solo. Em virtude deste contexto, foi
realizada neste trabalho uma vasta pesquisa, no campo dos sistemas
de software auto adapt{\'a}veis, apresentados conceitos e um
framework denominado Arctic Fox, que permite um sistema de
Segmento de Solo alterar suas condi{\c{c}}{\~o}es estruturais e
toda a sua din{\^a}mica. Esta adapta{\c{c}}{\~a}o {\'e}
realizada pela implementa{\c{c}}{\~a}o de duas classes de
conhecimento fundamentais o Conhecimento Contextual (Estrutura do
Sistema) e o Conhecimento Situacional (Din{\^a}mica e
Comportamento do Sistema), elementos estes respons{\'a}veis pela
tomada de decis{\~a}o de adapta{\c{c}}{\~a}o. V{\'a}rios
elementos comp{\~o}em este conhecimento como os Componentes de
Sistemas existentes (Servi{\c{c}}os), elementos de hardware e
principalmente as m{\'e}tricas de Qualidade de servi{\c{c}}o. A
utiliza{\c{c}}{\~a}o deste conhecimento {\'e} realizada
atrav{\'e}s do Modelo MAPE-K, que proporciona o monitoramento, a
an{\'a}lise, o planejamento e a execu{\c{c}}{\~a}o das
altera{\c{c}}{\~o}es estruturais e comportamentais do sistema. A
base de conhecimento {\'e} atualizada por elementos
respons{\'a}veis pela aquisi{\c{c}}{\~a}o do conhecimento, que
reflete as inclus{\~o}es e as altera{\c{c}}{\~o}es dos estados
dos elementos que comp{\~o}em a arquitetura do Sistema Solo. De
maneira a avaliar o framework proposto, foi implementado um
prot{\'o}tipo, e um estudo de caso para o EMBRACE. (programa de
Estudo e Monitoramento BRAsileiro de Clima Espacial) do INPE. Os
sistemas de solo do Clima Espacial s{\~a}o respons{\'a}veis pelo
armazenamento, processamento e dissemina{\c{c}}{\~a}o de dados
de diversos tipos de instrumentos. Desta forma,
situa{\c{c}}{\~o}es como a inoper{\^a}ncia de um instrumento,
ou falha em algum servidor, produzem impacto na
opera{\c{c}}{\~a}o regular do Sistema Solo, com
degrada{\c{c}}{\~a}o da qualidade do servi{\c{c}}o prestado
para a miss{\~a}o. No estudo de caso em quest{\~a}o, a
utiliza{\c{c}}{\~a}o do framework {\'e} exercitada e
atrav{\'e}s de um experimento controlado foram analisados os
impactos da auto-adapta{\c{c}}{\~a}o. Utilizando
solicita{\c{c}}{\~o}es de uso de um servi{\c{c}}o
t{\'{\i}}pico do EMBRACE, o Gtex, verificouse ganhos para a
disponibilidade do sistema, via a observa{\c{c}}{\~a}o da Taxa
de Sucesso da chamada ao Servi{\c{c}}o. Desta forma, conclui-se
neste experimento que o uso do framework contribui de forma
significativa para a Qualidade do Sistema. ABSTRACT: Space systems
architectures are composed of three segments: space segment,
ground systems and launchers. The space segment, in recent years
has driven lots of technological innovations, such as cubesats.
These new kinds of technologies produce impacts such as decreasing
of the size of satellites and increasing the amount of objects in
space. Thus, instead of adopting large satellites in space
missions, constellations and mega constellations of very small
satellites are used. These architectural changes produce a large
number of satellites that must be controlled simultaneously and
have their large amount of data processed, most of the time, in
real time by the ground systems. In this work, a vast research of
self-adaptive software systems was carried out, concepts and a
framework called Arctic Fox are presented. Using the framework the
ground systems can have their structural elements and behavior
conditions changed. This adaptation is accomplished by the
implementation of two fundamental knowledge classes that are used
for decision making: Context Awareness (Structural) and
Situational Awareness (Behavior). This knowledge is composed by
several elements such as the existing system components
(services), hardware elements and especially the quality of
service metrics. The use of this knowledge is performed through
the MAPE-K model, which provides the monitoring, analysis,
planning and execution of adaptations in the ground systems. The
knowledge base is updated by elements responsible for the
knowledge acquisition, which reflects the inclusions and the
changes of the elements states that compose the ground System
architecture. In order to evaluate the proposed framework, a
prototype was implemented, and a case study for the Brazilian
Space Weather Program EMBRACE of INPE is conducted. The {"}Space
Weather Systems{"} are responsible for the storage, processing and
data dissemination of different types of instruments. In this way,
situations such as some instrument data provider or server
computers failure, impact the regular ground systems operation,
with degradation of the service quality provided by the mission.
In the stated case study, the use of the framework is exercised
and through a controlled experiment the impacts of self-adaptation
were analyzed. Using services calls and derived {"}success rate{"}
metrics to a typical EMBRACE service, Gtex Service, availability
gains was observed. The experiment demonstrates that the use of
the framework contributes significantly to improve the ground
systems segment quality.",
committee = "Ferreira, Maur{\'{\i}}cio Gon{\c{c}}alves Vieira (presidente)
and Sant'Anna, Nilson (orientador) and Mattiello Francisco, Maria
de F{\'a}tima and Santos, Walter Abrah{\~a}o dos and Silveira,
F{\'a}bio Fagundes and Arakaki, Reinaldo Gen Ichiro",
englishtitle = "A framework to provide self-adaptive support to space ground
systems",
language = "pt",
pages = "193",
ibi = "8JMKD3MGP3W34R/3QRDJ45",
url = "http://urlib.net/ibi/8JMKD3MGP3W34R/3QRDJ45",
targetfile = "publicacao.pdf",
urlaccessdate = "30 abr. 2024"
}