@PhDThesis{Joshi:2021:MuAnMo,
               author = "Joshi, Neelakshi",
                title = "Multifractal analysis and modeling of time series for 
                         characterizing nonhomogeneous turbulence in space physics",
               school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                 year = "2021",
              address = "S{\~a}o Jos{\'e} dos Campos",
                month = "2020-04-22",
             keywords = "MFDFA, DFA, p model, space plasma irregularities, solar type I 
                         noise storm, irregularidades plasma espacial, emiss{\~a}o solar 
                         de tempestade de ru{\'{\i}}do do tipo I.",
             abstract = "Many dynamic processes in space physics can be investigated from 
                         the study of nonlinear fluctuations observed from instruments with 
                         high temporal and spectral resolution. In this thesis, it is 
                         presented, for the first time, the characterization of 
                         inhomogeneous turbulence as a possible cause of the spectral 
                         deviations found for the variables associated with the instability 
                         of the ionospheric and solar plasma. Algorithms based on 
                         formalisms for the analysis of monofractal and multifractal 
                         detrended fluctuation (DFA-MFDFA) were implemented. To validate 
                         the results obtained from the multifractal analysis, the 
                         theoretical framework for the energy cascade, based on twoscale 
                         Cantor set, a formalism known as the p model, was also 
                         implemented, tested and used. The multiplicity of intermittent 
                         behavior of plasma irregularities in the Type I solar emissions, 
                         the ionospheric F region and the E-F valley region were 
                         characterized by the MFDFA, including the respective validations 
                         through the p model spectra. The multifractal spectra are 
                         presented for the three case studies in space physics. In all 
                         three cases, the hypothesis of a non homogeneous multiplicative 
                         cascade process for the distribution of turbulent energy is 
                         confirmed by the spectra. Also, the same analytical computational 
                         procedure has been discussed for applications in complex systems 
                         in general, considering, for example, the modelling of armed 
                         conflict time series. RESUMO: Muitos processos din{\^a}micos em 
                         f{\'{\i}}sica espacial podem ser investigados a partir do estudo 
                         de flutua{\c{c}}{\~o}es n{\~a}o-lineares observadas a partir de 
                         instrumentos com alta resolu{\c{c}}{\~a}o temporal e espectral. 
                         Nesta tese, {\'e} apresentada, pela primeira vez, a 
                         caracteriza{\c{c}}{\~a}o de turbul{\^e}ncia n{\~a}o 
                         homog{\^e}nea como poss{\'{\i}}vel causa dos desvios espectrais 
                         encontrados para as vari{\'a}veis associadas {\`a} instabilidade 
                         do plasma ionosf{\'e}rico e solar. Algoritmos baseados nos 
                         formalismos para a an{\'a}lise de flutua{\c{c}}{\~a}o 
                         destendenciada monofractal e multifractal (DFA-MFDFA) foram 
                         implementados. Para validar os resultados obtidos da an{\'a}lise 
                         multifractal, o framework te{\'o}rico baseado no conjunto de 
                         Cantor de duas escalas, formalismo conhecido como cascata p model, 
                         tamb{\'e}m foi implementado, testado e utilizado para validar dos 
                         resultados espectrais. A multiplicidade de comportamentos 
                         intermitentes das irregularidades no plasma das emiss{\~o}es 
                         solares do Tipo I, da regi{\~a}o F ionosf{\'e}rica e da 
                         regi{\~a}o do vale E-F foram caracterizadas por an{\'a}lise de 
                         flutua{\c{c}}{\~a}o destendenciada multifractal, incluindo as 
                         respectivas valida{\c{c}}{\~o}es atrav{\'e}s do espectros do p 
                         model. Os espectros multifractais s{\~a}o apresentados para os 
                         tr{\^e}s casos de estudo em f{\'{\i}}sica espacial. Nos 
                         tr{\^e}s casos, a hip{\'o}tese de exist{\^e}ncia de processo de 
                         cascata multiplicativa n{\~a}o homog{\^e}nea para a 
                         distribui{\c{c}}{\~a}o de energia turbulenta {\'e} confirmada 
                         pelos espectros. Tamb{\'e}m discutimos o mesmo procedimento 
                         computacional anal{\'{\i}}tico para aplica{\c{c}}{\~o}es em 
                         sistemas complexos em geral, considerando, por exemplo, a 
                         modelagem de s{\'e}ries temporais de conflitos armados.",
            committee = "Velho, Haroldo Fraga de Campos (presidente) and Rosa, Reinaldo 
                         Roberto (orientador) and Stephany, Stephan (orientador) and 
                         Fernandes, Francisco Carlos Rocha and Alejandro Valdivia, Juan",
         englishtitle = "An{\'a}lise do multifractal e cascade p model para caracterizar 
                         n{\~a}o homog{\^e}nio turbul{\^e}ncia na f{\'{\i}}sica 
                         espacial",
             language = "en",
                pages = "119",
                  ibi = "8JMKD3MGP3W34R/42BG88H",
                  url = "http://urlib.net/ibi/8JMKD3MGP3W34R/42BG88H",
           targetfile = "publicacao.pdf",
        urlaccessdate = "19 abr. 2024"
}