438 research outputs found

    Gerenciamento de restrições de integridade para dados geoespaciais multi-escala

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    Orientador: Claudia Maria Bauzer MedeirosDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Trabalhar em questões relativas a dados geoespaciais presentes em múltiplas escalas apresenta inúmeros desafios que têm sido atacados pelos pesquisadores da área de GIS (Sistemas de Informação Geográfica). De fato, um dado problema do mundo real deve frequentemente ser estudado em escalas distintas para ser resolvido. Outro fator a ser considerado é a possibilidade de manter o histórico de mudanças em cada escala. Além disso, uma das principais metas de ambientes multi-escala _e garantir a manipulação de informações sem qualquer contradição entre suas diferentes representações. A noção de escala extrapola inclusive a questão espacial, pois se aplica também, por exemplo, _a escala temporal. Estes problemas serão analisados nesta dissertação, resultando nas seguintes contribuições: (a) proposta do modelo DBV (Database Version) multi-escala para gerenciar de forma transparente dados de múltiplas escalas sob a perspectiva de bancos de dados; (b) especificação de restrições de integridade multi-escala; (c) implementação de uma plataforma que suporte o modelo e as restrições, testados com dados reais multi-escalaAbstract: Work on multi-scale issues concerning geospatial data presents countless challenges that have been long attacked by GIScience (Geographic Information Science) researchers. Indeed, a given real world problem must often be studied at distinct scales in order to be solved. Another factor to be considered is the possibility of maintaining the history of changes at each scale. Moreover, one of the main goals of multi-scale environments is to guarantee the manipulation of information without any contradiction among the different representations. The concept of scale goes beyond issues of space, since it also applies, for instance, to time. These problems will be analyzed in this thesis, resulting in the following contributions: (a) the proposal of the DBV (Database Version) multi-scale model to handle data at multiple scales from a database perspective; (b) the specification of multi-scale integrity constraints; (c) the implementation of a platform to support model and constraints, tested with real multi-scale dataMestradoCiência da ComputaçãoMestre em Ciência da Computaçã

    Análise colaborativa de grandes conjuntos de séries temporais

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    The recent expansion of metrification on a daily basis has led to the production of massive quantities of data, and in many cases, these collected metrics are only useful for knowledge building when seen as a full sequence of data ordered by time, which constitutes a time series. To find and interpret meaningful behavioral patterns in time series, a multitude of analysis software tools have been developed. Many of the existing solutions use annotations to enable the curation of a knowledge base that is shared between a group of researchers over a network. However, these tools also lack appropriate mechanisms to handle a high number of concurrent requests and to properly store massive data sets and ontologies, as well as suitable representations for annotated data that are visually interpretable by humans and explorable by automated systems. The goal of the work presented in this dissertation is to iterate on existing time series analysis software and build a platform for the collaborative analysis of massive time series data sets, leveraging state-of-the-art technologies for querying, storing and displaying time series and annotations. A theoretical and domain-agnostic model was proposed to enable the implementation of a distributed, extensible, secure and high-performant architecture that handles various annotation proposals in simultaneous and avoids any data loss from overlapping contributions or unsanctioned changes. Analysts can share annotation projects with peers, restricting a set of collaborators to a smaller scope of analysis and to a limited catalog of annotation semantics. Annotations can express meaning not only over a segment of time, but also over a subset of the series that coexist in the same segment. A novel visual encoding for annotations is proposed, where annotations are rendered as arcs traced only over the affected series’ curves in order to reduce visual clutter. Moreover, the implementation of a full-stack prototype with a reactive web interface was described, directly following the proposed architectural and visualization model while applied to the HVAC domain. The performance of the prototype under different architectural approaches was benchmarked, and the interface was tested in its usability. Overall, the work described in this dissertation contributes with a more versatile, intuitive and scalable time series annotation platform that streamlines the knowledge-discovery workflow.A recente expansão de metrificação diária levou à produção de quantidades massivas de dados, e em muitos casos, estas métricas são úteis para a construção de conhecimento apenas quando vistas como uma sequência de dados ordenada por tempo, o que constitui uma série temporal. Para se encontrar padrões comportamentais significativos em séries temporais, uma grande variedade de software de análise foi desenvolvida. Muitas das soluções existentes utilizam anotações para permitir a curadoria de uma base de conhecimento que é compartilhada entre investigadores em rede. No entanto, estas ferramentas carecem de mecanismos apropriados para lidar com um elevado número de pedidos concorrentes e para armazenar conjuntos massivos de dados e ontologias, assim como também representações apropriadas para dados anotados que são visualmente interpretáveis por seres humanos e exploráveis por sistemas automatizados. O objetivo do trabalho apresentado nesta dissertação é iterar sobre o software de análise de séries temporais existente e construir uma plataforma para a análise colaborativa de grandes conjuntos de séries temporais, utilizando tecnologias estado-de-arte para pesquisar, armazenar e exibir séries temporais e anotações. Um modelo teórico e agnóstico quanto ao domínio foi proposto para permitir a implementação de uma arquitetura distribuída, extensível, segura e de alto desempenho que lida com várias propostas de anotação em simultâneo e evita quaisquer perdas de dados provenientes de contribuições sobrepostas ou alterações não-sancionadas. Os analistas podem compartilhar projetos de anotação com colegas, restringindo um conjunto de colaboradores a uma janela de análise mais pequena e a um catálogo limitado de semântica de anotação. As anotações podem exprimir significado não apenas sobre um intervalo de tempo, mas também sobre um subconjunto das séries que coexistem no mesmo intervalo. Uma nova codificação visual para anotações é proposta, onde as anotações são desenhadas como arcos traçados apenas sobre as curvas de séries afetadas de modo a reduzir o ruído visual. Para além disso, a implementação de um protótipo full-stack com uma interface reativa web foi descrita, seguindo diretamente o modelo de arquitetura e visualização proposto enquanto aplicado ao domínio AVAC. O desempenho do protótipo com diferentes decisões arquiteturais foi avaliado, e a interface foi testada quanto à sua usabilidade. Em geral, o trabalho descrito nesta dissertação contribui com uma abordagem mais versátil, intuitiva e escalável para uma plataforma de anotação sobre séries temporais que simplifica o fluxo de trabalho para a descoberta de conhecimento.Mestrado em Engenharia Informátic

    Integrierter Ansatz zur konzeptionellen Datenmodellierung eines geographischen Informationssystems (GIS) für Daten der Straßenverwaltung

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    Um ihre Aufgaben zu verwirklichen, sind Straßenverwaltungen in aller Welt dazu aufgefordert, neue Technologien einzuführen. Grund dafür ist die große Menge an anfallenden Informationen des Straßennetzes und die Notwendigkeit Datenquellen effizient zu nutzen. Geoinformationssysteme für das Transportwesen (GIS-T), welche speziell für Straßenverwaltungen entwickelt wurden, bewirken eine erhebliche Effizienzsteigerung, da sie am besten in der Lage sind, dem räumlichen Charakter der Daten Rechnung zu tragen. Häufig wurde dieser räumliche Charakter der Informationen bei der Systementwicklung ungenügend beachtet, was dazu führte, dass die Möglichkeiten solcher Systeme nicht voll ausgeschöpft wurden. Die Implementierung eines Systems kann nur dann zu vollem Erfolg führen, wenn eine detaillierte Informationsstrukturanalyse durchgeführt wird und wenn die Datenmodellierung formalisierten Entwurfsmethoden folgt. Im Verlauf der Untersuchungen wurde festgestellt, dass gebräuchliche Systeme verschiedene Anforderungen von Straßenverwaltungen nicht erfüllen. Die Probleme können wie folgt zusammengefasst werden:Die Beziehungen zwischen geometrischen, topologischen und Sachinformationen wurden nicht strukturiert. Die Abbildung von geometrischen Informationen in unterschiedlichen Referenzsystemen war nicht redundanzfrei möglich. Die Verwaltung topologischer Informationen in unterschiedlichen Abstraktionsebenen wurde nicht realisiert. Spezifische Funktionen der Straßenverwaltung wurden nicht in ihrer Gesamtheit abgebildet. Nicht alle existierenden Informationen und Methoden konnten in die Systeme integriert werden. Es ist erforderlich, Metadaten wie Konsistenzbedingungen, Qualitätsangaben und Historisierung im System zu berücksichtigen. Speziell für die Definition von systemübergreifend eindeutigen Objektidentifikatoren sind neue Ansätze erforderlich.Um die Effizienz von GIS-T zu verbessern und die beschriebenen Anforderungen zu erfüllen, wird in der vorliegenden Arbeit schrittweise ein Ansatz für eine konzeptionelle Datenmodellierung vorgestellt, welche den Bedürfnissen einer Straßenverwaltung Rechnung trägt. Der Grundgedanke des vorgeschlagenen Modells besteht in der Abstraktion und der strengen Unterscheidung von geometrischen, topologischen und Sachdaten. Um die Integration aller Daten, die Kontrolle von Redundanz und eine Optimierung der Datenpflege zu erreichen, wurden Trassierungselemente durch datumsinvariante Parameter abgebildet. Das vorgeschlagene konzeptionelle Datenmodell wurde erfolgreich implementiert. Dabei kam ein objektrelationales Datenbanksystem zum Einsatz.World-wide highway administrations are stressed to implementnew technologies, due to the large amount of information associated with highway networks and the necessity of using sources efficiently in order to realize their tasks. Geographic Information Systems-Transportation (GIS-T), which are specifically tailored for highway administrations, are identified having the highest information technology payoff potential by the highway administrations due to road information spatial character. Contrarily, road information spatial character is not adequately considered during system design, as a result, many of the benefits of GIS-T are not fully realized and efficiency of this technology is mainly under estimated. The relative success of implemented system is not clear without a detailed information analysis and a data model, which rely on formal data model design methodologies.It was determined during this study that several demands of highway administrations were not responded by means of current systems. These topics can be summarized as follows; relationships among geometry, topology and thematic information were not structured. The geometry information can notbe mapped in various reference systems without redundancy. The non-planar multi- abstraction topological information was not exist. The entire highway administrations business rules can not be performed in the current systems. The existing information and methods were not integrated into the system. The metadata including consistency rules, quality specifications and history information needed to be incorporated into the system. Especially in order to determine permanent, non-spatial and a unique object identifier,regulations and new approaches are required. In order to increase the efficiency of GIS-T and fulfill these requirements, this study considered a progressive approach appropriate to the conceptual data modeling requirements of an entire highway agency. The main approach of the proposed data model was abstraction and decomposition of geometry,topology and non-spatial data. In order to achieve data integration, control of redundancy and optimization of data maintenance, linear elements were mapped by means of datum invariant parameters. The proposed conceptual data model was successfully implemented using the integrated approach in one object-relational system

    Engineering Agile Big-Data Systems

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    To be effective, data-intensive systems require extensive ongoing customisation to reflect changing user requirements, organisational policies, and the structure and interpretation of the data they hold. Manual customisation is expensive, time-consuming, and error-prone. In large complex systems, the value of the data can be such that exhaustive testing is necessary before any new feature can be added to the existing design. In most cases, the precise details of requirements, policies and data will change during the lifetime of the system, forcing a choice between expensive modification and continued operation with an inefficient design.Engineering Agile Big-Data Systems outlines an approach to dealing with these problems in software and data engineering, describing a methodology for aligning these processes throughout product lifecycles. It discusses tools which can be used to achieve these goals, and, in a number of case studies, shows how the tools and methodology have been used to improve a variety of academic and business systems
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