Componentes e pontos de quebra em séries temporais na análise de imagens de sensoriamento remoto

Orientador: Ricardo da Silva TorresDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: A detecção e caracterização de mudanças temporais são indicadores cruciais no processo de compreensão da maneira como mecanismos complexos funcionam e evoluem. Técnicas e imagens de sensoriamento remoto têm sido amplamente empregadas nas últimas décadas com objetivo de detectar e investigar mudanças temporais na superfície terrestre. Tal detecção em dados de séries temporais é passível de ser refinada ainda mais isolando-se as componentes aditivas de tendência e sazonalidade do ruído subjacente. Este trabalho investiga, em particular, o método Breaks For Additive Season and Trend (BFAST) para a análise, decomposição e detecção de pontos de quebra em séries temporais associadas a dados de sensoriamento remoto. Os outputs do método são, então, utilizados em três distintas ¿ mas altamente interconectadas ¿ linhas de pesquisa: em uma melhor compreensão de fenômenos climáticos; na correlação com dados de distúrbios antropológicos; e em problemas de classificação usando funções de dissimilaridade descobertas por um framework evolucionário baseado em Programação Genética (GP). Experimentos realizados demonstram que a decomposição e pontos de quebra produziram resultados efetivos quando aplicados aos estudos com dados ecológicos, mas não foram capazes de melhorar os resultados de classificação quando comparados ao uso das séries brutas. As realizações nesses três contextos também culminaram na criação de duas ferramentas de análise de séries temporais com código aberto baseadas na web, sendo que uma delas foi tão bem aceita pela comunidade-alvo, que atualmente encontra-se integrada em uma plataforma privada de computação em nuvemAbstract: Detecting and characterizing temporal changes are crucial indicators in the process of understanding how complex mechanisms work and evolve. The use of remote sensing images and techniques has been broadly employed over the past decades in order to detect and investigate temporal changes on the Earth surface. Such change detection in time series data may be even further refined by isolating the additive long-term (trend) and cyclical (seasonal) components from the underlying noise. This work investigates the particular Breaks For Additive Season and Trend (BFAST) method for the analysis, decomposition, and breakpoint detection of time series associated with remote sensing data. The derived outputs from that method are, then, used in three distinct ¿ but highly interconnected ¿ research venues: in a better comprehension of climatic phenomena; in the correlation to human-induced disturbances data; and in data classification problems using time series dissimilarity functions discovered by a Genetic-Programming-(GP)-based evolutionary framework. Performed experiments show that decomposition and breakpoints produced insightful and effective results when applied to the ecological data studies, but could not further improve the classification results when compared to its raw time series counterpart. The achievements in those three contexts also led to the creation of two open-source web-based time series analysis tools. One of those tools was so well received by the target community, that it is currently integrated into a private cloud computing platformMestradoCiência da ComputaçãoMestre em Ciência da Computação132847/2015-92015/02105-0CNPQFAPES

Multiresolution community detection for megascale networks by information-based replica correlations

We use a Potts model community detection algorithm to accurately and quantitatively evaluate the hierarchical or multiresolution structure of a graph. Our multiresolution algorithm calculates correlations among multiple copies ("replicas") of the same graph over a range of resolutions. Significant multiresolution structures are identified by strongly correlated replicas. The average normalized mutual information, the variation of information, and other measures in principle give a quantitative estimate of the "best" resolutions and indicate the relative strength of the structures in the graph. Because the method is based on information comparisons, it can in principle be used with any community detection model that can examine multiple resolutions. Our approach may be extended to other optimization problems. As a local measure, our Potts model avoids the "resolution limit" that affects other popular models. With this model, our community detection algorithm has an accuracy that ranks among the best of currently available methods. Using it, we can examine graphs over 40 million nodes and more than one billion edges. We further report that the multiresolution variant of our algorithm can solve systems of at least 200000 nodes and 10 million edges on a single processor with exceptionally high accuracy. For typical cases, we find a super-linear scaling, O(L^{1.3}) for community detection and O(L^{1.3} log N) for the multiresolution algorithm where L is the number of edges and N is the number of nodes in the system.Comment: 19 pages, 14 figures, published version with minor change

Interests and Expectations of the Confederated Tribes of the Umatilla Indian Reservation Regarding Hanford and Hanford-Affected Lands

This document updates the previous document “Scoping Report: Nuclear Risks in Tribal Communities” prepared by Confederated Tribes of the Umatilla Indian Reservation (CTUIR) in 1995. At the time, “no comprehensive or sitewide evaluation of risks and costs has been performed at Hanford.” A decade later, this is still true. It is also still true that “a full risk picture must include addressing the impacts over time.” This report provides a more docused perspective on how to establish both technically and politically defensible environmental management approach in an era of continued fiscal constraints. This was true in 1995 and is even more constraining in 2006. A major stakeholder-driven document was written in 1996 (Columbia River Comprehensive Impact Assessment, Part II). We believe that an investment by the Department of Energy (DOE) in a more effective and efficient risk assessment approach as well as increased emphasis on integration of Natural Resource Damage Assessment (NRDA) and Stewardship into the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) process will ultimately save the DOE money by reducing future maintainence and other costs. This research was completed money allocated during Round 6 of the Citizens’ Monitoring and Technical Assessment Fund (MTA Fund). Clark University was named conservator of these works. If you have any questions or concerns please contact us at [email protected]://commons.clarku.edu/umatilla/1000/thumbnail.jp

Text-organizing metadiscourse: Tracking changes in rhetorical persuasion

Published academic writing often seems to be an unchanging form of discourse with its frozen informality remaining stable over time. Recent work has shown, however, that these texts are highly interactive and dialogic as writers anticipate and take into account readers' likely objections, background knowledge, rhetorical expectations and processing needs. In this paper, we explore one aspect of these interactions and how it has changed over the past fifty years. Focusing on what has been called interactive metadiscourse (Hyland 2005; Hyland and Tse 2004), or the ways authors organise their material for particular readers, we analyze a corpus of 2.2 million words compiled from articles in the top journals in four disciplines to discover whether, and to what extent, interactive metadiscourse has changed in different disciplines since 1965. The results show a considerable increase in an orientation to the reader over this period, reflecting changes in both research and publication practices

2D growth processes: SLE and Loewner chains

This review provides an introduction to two dimensional growth processes. Although it covers a variety processes such as diffusion limited aggregation, it is mostly devoted to a detailed presentation of stochastic Schramm-Loewner evolutions (SLE) which are Markov processes describing interfaces in 2D critical systems. It starts with an informal discussion, using numerical simulations, of various examples of 2D growth processes and their connections with statistical mechanics. SLE is then introduced and Schramm's argument mapping conformally invariant interfaces to SLE is explained. A substantial part of the review is devoted to reveal the deep connections between statistical mechanics and processes, and more specifically to the present context, between 2D critical systems and SLE. Some of the SLE remarkable properties are explained, as well as the tools for computing with SLE. This review has been written with the aim of filling the gap between the mathematical and the physical literatures on the subject.Comment: A review on Stochastic Loewner evolutions for Physics Reports, 172 pages, low quality figures, better quality figures upon request to the authors, comments welcom

An Instructional Sequence in Music Education Using Vocal and Instrumental Music of Five World Cultures.

The music of five non-Western cultures was incorporated in an instructional sequence for elementary grades (K)1-6. Traditional music of the Australian Aborigines and the Akan and Ewe tribes of Ghana, classical music of India, the music of the Indonesian gamelan, and Gagaku music of Japan were examined for the presence of musical concepts, the way each culture handles the concepts that are present, and the interrelationships that exist among the concepts. The music is described in terms of the musical concepts of dynamics, timbre, texture, rhythm, melody, harmony, and form. All of the concepts and their related percepts are organized into an instructional sequence of four levels. Listening examples which illustrate the concepts and percepts are also a part of the instructional sequence. This report investigated both vocal and instrumental music from Australia, Africa, India, Indonesia, and Japan

Theoretical implicatons of comparative survey research: why the wheel of cross-cultural methodology keeps on being reinvented

Der vorliegende Beitrag resümiert einige frühere Arbeiten zu methodologischen Problemen der vergleichenden Sozialforschung. Der Autor konstatiert keine entscheidenden Fortschritte, sondern sieht eher die Gefahr, daß gegenwärtig hinter die erreichten methodologischen Standards zurückgefallen wird. Im Zentrum der Ausführungen steht 'Galton's Problem', d.h. die Annahme, daß die untersuchten Länder voneinander unabhängige Fälle sind. Diese Annahme führt zu Schwierigkeiten bei der Behandlung von Fragen von nationaler und kultureller Diffusion und der Überprüfung von 'one-point measurements'. Vergleichende Forschung impliziert Mehrebenenansätze. Die Bedeutung der nationalen Kontexte sollte daher theoretisch stärker berücksichtigt werden. (pmb)'Reviewing the earlier literature on methodological issues in comparative research, the paper argues that 'in terms of methodology in abstracto and on issues of research technology, most of all that needed to be said has already been published.' Yet the actual research falls short of this available knowledge. Famous publications based on comparative research are really promulgators of research artefacts. Three goals are being emphasized: (a) to counteract the tendency to reinvent the methodological wheel; (b) to help with ex post interpretations of data from cross-national research; (c) to use the difficulties and pay-offs in comparisons for substantive insights. Thus, 'Galton's Problem' - treating countries as independent cases - forces an evaluation of the pervasiveness of diffusion vs. cultural/national identity. The low stability of many measures requires rethinking the meaning of one-point measurements. Comparative surveys are by implication cross-level research. Therefore, the use of country-names as explanans requires theoretical notions about the nation as context for actors and institutions.' (author's abstract