Fouille visuelle de données temporelles avec DataTube2

International audienceNous nous intéressons dans cet article à la fouille visuelle de données temporelles, où les données ont été mises sous la forme de n attributs dont les valeurs sont enregistrées pendant k instants. Après un état de l'art sur les différentes approches de visualisation de telles séries, nous présentons plus particulièrement une approche ayant reçue encore peu d'attention ("DataTube"). DataTube place les données dans un tube dont l'axe représente le temps. Nous étendons ensuite cette approche : tout d'abord nous définissons plusieurs modes de visualisations (couleurs, formes, etc) et nous ajoutons un axe temporel. Ensuite nous introduisons des interactions avec la possibilité de sélectionner des attributs et des instants, afficher des données complexes ou encore insérer des annotations sur la visualisation. Nous ajoutons une étape de classification non supervisée afin de regrouper dans la visualisation les attributs similaires. Enfin nous intégrons cette visualisation dans notre plateforme de fouille de données en réalité virtuelle VRMiner, avec un affichage stéréoscopique et des possibilités de navigation interactive. Nous appliquons cette visualisation sur plusieurs ensembles de données réelles et nous montrons qu'elle peut gérer jusqu'à 1,5 million de valeurs. Nous présentons également une évaluation utilisateur

RadialPheno: A tool for near-surface phenology analysis through radial layouts

Premise Increasingly, researchers studying plant phenology are exploring novel technologies to remotely observe plant changes over time. The increasing use of phenocams to monitor leaf phenology, based on the analysis of indices extracted from sequences of daily digital vegetation images, has demanded the development of appropriate tools for data visualization and analysis. Here, we describe RadialPheno, a tool that uses radial layouts to represent time series from digital repeat photographs, and applies them to the analysis of leafing patterns and leaf exchange strategies of different vegetations. Methods and Results We developed a web tool, RadialPheno, provided with the R and Shiny environments, which uses radial visual structures to represent cyclical multidimensional temporal data associated with digital image time series. We demonstrate the application of our methods and tool for a savanna vegetation phenology in the Brazilian Cerrado. We visually represented the greenness index extracted from sequential imagery using the RadialPheno tool. Conclusions RadialPheno was successfully applied for the visualization and interpretation of individual, species, and community long-term leafing phenology data associated with near-surface phenological observations of Cerrado vegetation. RadialPheno was also effective for intercomparisons of ground-based direct visual observations and camera-derived phenology observations

Adoption of a visual model for temporal database representation

Today, in the world of information technology, conceptual model representation of database schemas is challenging for users both in the Software Development Life Cycle (SDLC) and the Human-Computer Interaction (HCI) domain. The primary way to resolve this issue, in both domains, is to use a model that is concise, interpretable and clear to understand, yet encompasses all of the required information to be able to clearly define the database. A temporal database is understood as a database capable of supporting reasoning of time-based data for e.g.: a temporal database can answer questions such as: - for what period was Mrs Jones single before she got married? On the other hand, an atemporal database stores data that is valid today and has no history. In the thesis, I looked at different theoretical temporal visual conceptual models proposed by temporal researchers and aimed, by means of a user-survey consisting of business users, to ascertain towards which models users a preference has. I further asked the users for firstly; whether they prefer textual or graphical representations for the entities, attributes and constraints represented by the visual models, or secondly; whether there is a preference for a specific graphical icon for the temporal entities and lastly; to ascertain if the users show a preference towards a specific theoretical temporal conceptual model. The methodology employed to reach my goal in this thesis, is one of experiments on business users with knowledge enhancements after each experiment. Users were to perform a task, and then based on analysis of the task results, they are taught additional temporal aspects so as improve their knowledge before the next experiment commences. The ultimate aim was to extract a visual conceptual model preference from business users with enhanced knowledge of temporal aspects. This is the first work done in this field and thus will aid researchers in future work, as they will have a temporal conceptual model that promotes effective communication, understandability and interpretability

Visualização de padrões temporais cíclicos em estudos de fenologia

Orientadores: Ricardo da Silva Torres, Leonor Patrícia Cerdeira MorellatoTese (doutorado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Em diversas aplicações, grandes volumes de dados multidimensionais têm sido gerados continuamente ao longo do tempo. Uma abordagem adequada para lidar com estas coleções consiste no uso de métodos de visualização de informação, a partir dos quais padrões de interesse podem ser identificados, possibilitando o entendimento de fenômenos temporais complexos. De fato, em diversos domínios, o desenvolvimento de ferramentas adequadas para apoiar análises complexas, por exemplo, aquelas baseadas na identificação de padrões de mudanças ou correlações existentes entre múltiplas variáveis ao longo do tempo é de suma importância. Em estudos de fenologia, por exemplo, especialistas observam as mudanças que ocorrem ao longo da vida de plantas e animais e investigam qual é a relação entre essas mudanças com variáveis ambientais. Neste cenário, especialistas em fenologia cada vez mais precisam de ferramentas para, adequadamente, visualizar séries temporais longas, com muitas variáveis e de diferentes tipos (por exemplo, texto e imagem), assim como identificar padrões temporais cíclicos. Embora diversas abordagens tenham sido propostas para visualizar dados que variam ao longo do tempo, muitas não são apropriadas ou aplicáveis para dados de fenologia, porque não são capazes de: (i) lidar com séries temporais longas, com muitas variáveis de diferentes tipos de dados e de uma ou mais dimensões; e (ii) permitir a identificação de padrões temporais cíclicos e drivers ambientais associados. Este trabalho aborda essas questões a partir da proposta de duas novas abordagens para apoiar a análise e visualização de dados temporais multidimensionais. Nossa primeira proposta combina estruturas visuais radiais com ritmos visuais. As estruturas radiais são usadas para fornecer informação contextual sobre fenômenos cíclicos, enquanto que o ritmo visual é usado para sumarizar séries temporais longas em representações compactas. Nós desenvolvemos, avaliamos e validamos nossa proposta com especialistas em fenologia em tarefas relacionadas à visualização de dados de observação direta da fenologia de plantas em nível tanto de indivíduos quanto de espécies. Nós também validamos a proposta usando dados temporais relacionados a imagens obtidas de sistemas de monitoramento de vegetação próxima à superfície. Nossa segunda abordagem é uma nova representação baseada em imagem, chamada Change Frequency Heatmap (CFH), usada para codificar mudanças temporais de dados numéricos multivariados. O método calcula histogramas de padrões de mudanças observados em sucessivos instantes de tempo. Nós validamos o uso do CFH a partir da criação de uma ferramenta de caracterização de mudanças no ciclo de vida de plantas de múltiplos indivíduos e espécies ao longo do tempo. Nós demonstramos o potencial do CFH para ajudar na identificação visual de padrões de mudanças temporais complexas, especialmente na identificação de variações entre indivíduos em estudos relacionados à fenologia de plantasAbstract: In several applications, large volumes of multidimensional data have been generated continuously over time. One suitable approach for handling those collections in a meaningful way consists in the use of information visualization methods, based on which patterns of interest can be identified, triggering the understanding of complex temporal phenomena. In fact, in several domains, the development of appropriate tools for supporting complex analysis based, for example, on the identification of change patterns in temporal data or existing correlations, over time, among multiple variables, is of paramount importance. In phenology studies, for instance, phenologists observe changes in the development of plants and animals throughout their lives and investigate what is the relationship between these changes with environmental changes. Therefore, phenologists increasingly need tools for visualizing appropriately long-term series with many variables of different data types, as well as for identifying cyclical temporal patterns. Although several approaches have been proposed to visualize data varying over time, most of them are not appropriate or applicable to phenology data, because they are not able: (i) to handle long-term series with many variables of different data types and one or more dimensions and (ii) to support the identification of cyclical temporal patterns and associated environmental drivers. This work addresses these shortcomings by presenting two new approaches to support the analysis and visualization of multidimensional temporal data. Our first proposal to visualize phenological data combines radial visual structures along with visual rhythms. Radial visual structures are used to provide contextual insights regarding cyclical phenomena, while the visual rhythm encoding is used to summarize long-term time series into compact representations. We developed, evaluated, and validated our proposal with phenology experts using plant phenology direct observational data both at individuals and species levels. Also we validated the proposal using image-related temporal data obtained from near-surface vegetation monitoring systems. Our second approach is a novel image-based representation, named Change Frequency Heatmap (CFH), used to encode temporal changes of multivariate numerical data. The method computes histograms of change patterns observed at successive timestamps. We validated the use of CFHs through the creation of a temporal change characterization tool to support complex plant phenology analysis, concerning the characterization of plant life cycle changes of multiple individuals and species over time. We demonstrated the potential of CFH to support visual identification of complex temporal change patterns, especially to decipher interindividual variations in plant phenologyDoutoradoCiência da ComputaçãoDoutora em Ciência da Computação162312/2015-62013/501550-0CNPQCAPESFAPES

A generic multimedia configuration management system for constrained spatial user-interface design

This thesis examined two leading researchers within the fields of Design Science Research in Information Systems. The first was Peffers’ (DSRM), which is a six-step linear process model. The second model was Hevner’s, (DSRC), which is a three-stage design research cycle which comprises of an eight core structure. The process was to map the (GMCMSID) concept-of-prototype (which was the test programme for this thesis) over Peffers’ and Hevner methodology models. By mapping these two pre-existing models, one could ascertain that the GMCMSID artifact can be mapped successfully over these two theories, but certain questions of relevance at different points within the process cycles were raised. Where does the Creative Design cycle process begin within the Design Science in Information System processes model? Does an artifact at a proof-of-concept stage fulfill all of the relevant academic research required for a body of academic work? And can the GMCMSID concept-of-prototype project be successfully mapped over the DSRM and DSRC models, especially when it came to the Evaluation activity stage component within the design science process? The GMCMSID artifact was designed as a configuration management system for design and placements of widgets within the fuselage of a rotary wing aircraft such as the Black Hawk Helicopter, which is continually subjected to design changes to meet evolving engineering and capability requirements. The GMCMSID project allowed the Logistics Manager, Fleet Manager, and Configuration Manager, to reserve locations, internal and external to the aircraft, for future design changes to facilitate the comprehensive, efficient and cost effective design, planning and tracking of changes to the rotary wing fleet’s operational capabilities. The GMCMSID artifact explored the implications of new theoretical approaches to modeling aircraft maintenance, including the realistic configuration of mission capable aircraft for the following deployments, Special Operations, Troop Deployment and Medivac. The study found that the GMCMSID project mapped successfully over both Peffers’ and Hevner’s theological models, showing that a corporate base prototype which had already been designed and built to a concept-of-prototype stage does fall within the guidelines of research and development of an artifact. This study also showed that a concept-of-prototype to the Evaluation activity stage can be recognised as a significant body of research, but a problem does occur at the Evaluation stage as the artifact is still at a proof-of-concept stage and has had very limited field-testing applied to it. The implication of this is that the broader academic community may not accept an artifact at this early stage of development, as a significant research body of work. A new aspect that was brought to the fore in the study was where does creative design fit within the studies of Design Science in Information Systems? By using the GMCMSID project, one could say that the creative design process commenced at the conception of a project and concluded at the design stage of the artifact. Limited research has been carried out on creativity and design within Design Science in Information Systems field, but mostly on the environment around creativity, not where creativity commences or how it is measured. More in-depth research needs to be undertaken in relation to the concert-of-prototype stage of a project that is deemed to be a significant research contribution at the Evaluation activity stage and the process of creative design. In the body of this thesis, suggested guidelines have been incorporated for further discussion within this field. Also, a creative design activity model was developed to show where creative design fits within a Design Science in Information System methodology. Without creative design, you do not have the design