92 research outputs found

    An Analytics Platform for Integrating and Computing Spatio-Temporal Metrics

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    In large-scale context-aware applications, a central design concern is capturing, managing and acting upon location and context data. The ability to understand the collected data and define meaningful contextual events, based on one or more incoming (contextual) data streams, both for a single and multiple users, is hereby critical for applications to exhibit location- and context-aware behaviour. In this article, we describe a context-aware, data-intensive metrics platform —focusing primarily on its geospatial support—that allows exactly this: to define and execute metrics, which capture meaningful spatio-temporal and contextual events relevant for the application realm. The platform (1) supports metrics definition and execution; (2) provides facilities for real-time, in-application actions upon metrics execution results; (3) allows post-hoc analysis and visualisation of collected data and results. It hereby offers contextual and geospatial data management and analytics as a service, and allow context-aware application developers to focus on their core application logic. We explain the core platform and its ecosystem of supporting applications and tools, elaborate the most important conceptual features, and discuss implementation realised through a distributed, micro-service based cloud architecture. Finally, we highlight possible application fields, and present a real-world case study in the realm of psychological health

    HyDRA Hybrid workflow Design Recommender Architecture

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    Workflows are a way to describe a series of computations on raw e-Science data. These data may be MRI brain scans, data from a high energy physics detector or metric data from an earth observation project. In order to derive meaningful knowledge from the data, it must be processed and analysed. Workflows have emerged as the principle mechanism for describing and enacting complex e-Science analyses on distributed infrastructures such as grids. Scientific users face a number of challenges when designing workflows. These challenges include selecting appropriate components for their tasks, spec- ifying dependencies between them and selecting appropriate parameter values. These tasks become especially challenging as workflows become increasingly large. For example, the CIVET workflow consists of up to 108 components. Building the workflow by hand and specifying all the links can become quite cumbersome for scientific users.Traditionally, recommender systems have been employed to assist users in such time-consuming and tedious tasks. One of the techniques used by recommender systems has been to predict what the user is attempting to do using a variety of techniques. These techniques include using workflow se- mantics on the one hand and historical usage patterns on the other. Semantics-based systems attempt to infer a user’s intentions based on the available semantics. Pattern-based systems attempt to extract usage patterns from previously-constructed workflows and match those patterns to the workflow un- der construction. The use of historical patterns adds dynamism to the suggestions as the system can learn and adapt with “experience”. However, in cases where there are no previous patterns to draw upon, pattern-based systems fail to perform. Semantics-based systems, on the other hand infer from static information, so they always have something to draw upon. However, that information first has to be encoded into the semantic repository for the system to draw upon it, which is a time-consuming and tedious task in it self. Moreover, semantics-based systems do not learn and adapt with experience. Both approaches have distinct, but complementary features and drawbacks. By combining the two approaches, the drawbacks of each approach can be addressed.This thesis presents HyDRA, a novel hybrid framework that combines frequent usage patterns and workflow semantics to generate suggestions. The functions performed by the framework include; a) extracting frequent functional usage patterns; b) identifying the semantics of unknown components; and c) generating accurate and meaningful suggestions. Challenges to mining frequent patterns in- clude ensuring that meaningful and useful patterns are extracted. For this purpose only patterns that occur above a minimum frequency threshold are mined. Moreover, instead of just groups of specific components, the pattern mining algorithm takes into account workflow component semantics. This allows the system to identify different types of components that perform a single composite function. One of the challenges in maintaining a semantic repository is to keep the repository up-to-date. This involves identifying new items and inferring their semantics. In this regard, a minor contribution of this research is a semantic inference engine that is responsible for function b). This engine also uses pre-defined workflow component semantics to infer new semantic properties and generate more accurate suggestions. The overall suggestion generation algorithm is also presented.HyDRA has been evaluated using workflows from the Laboratory of Neuro Imaging (LONI) repos- itory. These workflows have been chosen for their structural and functional characteristics that help� to evaluate the framework in different scenarios. The system is also compared with another existing pattern-based system to show a clear improvement in the accuracy of the suggestions generated

    Photogrammetry as a surveying thechnique apllied to heritage constructions recording - avantages and limitations

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    Dissertação de Mestrado Integrado em Arquitetura, com a especialização em Arquitetura apresentada na Faculdade de Arquitetura da Universidade de Lisboa para obtenção do grau de Mestre.A presente dissertação tem por objectivo investigar e evidenciar as vantagens da aplicação da fotogrametria, e possíveis integrações com outros métodos de levantamento, como seja o varrimento laser terrestre, posicionamento por GPS, entre outros, para realizar levantamentos de construções patrimoniais ou eruditas e a respectiva produção de documentação base para viabilizar intervenções de conservação, restauro ou reabilitação. A motivação para a investigação advém da aplicação flexível, versátil, simples, acessível, e baixo-custo da fotogrametria em projectos de levantamento pequenos ou extensos. Tenciona-se igualmente colmatar as desvantagens tradicionais da fotogrametria, nomeadamente a transição entre espaços interiores e exteriores, e registo de espaços estreitos, de difícil acesso, e de geometrias complexas, num único projecto de documentação. Pretende-se ultrapassar estas dificuldades através da utilização máxima das potencialidades da fotogrametria com o uso de imagens olho de peixe e apenas como último recurso utilizar instrumentos complementares. No caso de estudo principal, o Castelo do Convento de Cristo, demonstra-se a aplicação dos métodos investigados. Nos casos de estudo secundários abordam-se problemas parcelares, desde elementos decorativos até à totalidade do edificado: Convento dos Capuchos, em Sintra; Alcáçova e trecho de muralha do Castelo de Sesimbra; Igreja de Stº André, em Mafra; entre outros. Os casos auxiliaram na determinação de procedimentos a generalizar posteriormente. Por fim, propõem-se algoritmos que auxiliam na produção de documentação.ABSTRACT: The present dissertation aims to research and demonstrate the advantages of the application of photogrammetry, and its possible integrations with other methods, such as terrestrial laser scanning, GPS positioning, and among others, to perform surveys of heritage or erudite buildings and respective production of base documentation to enable interventions of conservation, restoration, or rehabilitation. The motivation for researching is due to the flexible, versatile, simple, affordable, and low-cost application of photogrammetry in small and extensive survey projects. It is also intended to overcome the traditional disadvantages of photogrammetry, such as the transition between interior and exterior spaces, and difficulty of recording narrow, hard-to-access, and complex geometric spaces, in a single project. It is intended to overcome such challenges by maximizing the potential uses of photogrammetry with the use of fisheye images and by using other survey instruments as a last resort. In the main case study, the Castle of the Convent of Christ, the application of the investigated methods is demonstrated. In the secondary case studies, partial problems are addressed, ranging from decorative elements to the entire building: Convento dos Capuchos, in Sintra; Citadel and section of a wall of the Castle of Sesimbra; Igreja de St André, in Mafra; among others; The case studies aided in determining general procedures. Finally, algorithms that accelerate the production of documentation are proposed.N/

    Development of a hydrologic community modeling system using a workflow engine

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    Community modeling is a comparatively new paradigm that emphasizes on developing evolving modeling systems through a collective effort. It has gained growing attention within the hydrologic communities because the demand of developing more holistic-view model systems addressing chemical, physical, and biological processes within the geo volumes of the hydrologic cycle. The development of a community modeling system involves a number of technical issues including how to seamlessly integrate various models/modules especially to mediate their communications and executions, how to improve development efficiency by migrating legacy codes, and how to improve model provenance and repeatability of model runs to name just a few. The major objective of our studies is to develop a hydrologic community modeling system (HCMS) that allows constructing seamlessly integrated, workflow-based hydrologic models with swappable and portable modules for retrieving data from various data sources, pre-processing, modeling, and post-analysis. The HCMS is built on the Microsoft’s TRIDENT workflowengine which assists in tackling many of the above technical issues during its development. Four libraries are incorporated into HCMS, i.e. a data retrieval, a dataprocessing, a hydrologic computation and a data analysis library, which support to access data from numerous online data repositories using SOAP/FTP protocols or from local data stores, transform source data into model inputs, perform hydrologic modeling, and analyze model results, respectively. It can potentially be applied to anywhere in the nation due to its access to data sets of nationwide coverage, and can reduce the workload of conducting hydrologic modeling tasks to a great level. Besides its feature of supporting parallel or concurrent executions as well as distributing computations in GRID environment can improve run-time efficiency. This thesis comprises three independent papers, which present the studies on (1) the current efforts that have been or are beingmade for community modeling, (2) the development of the HCMS using the Microsoft’s TRIDENT workflow engine, (3) the assessment on the applicability and performance of the TRIDENT-shelled HCMS by applying it to conduct hydrologic studies on the Schuylkill watershed located in the Southeastern Pennsylvania.Ph.D., Civil Engineering -- Drexel University, 201

    Towards Interoperable Research Infrastructures for Environmental and Earth Sciences

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    This open access book summarises the latest developments on data management in the EU H2020 ENVRIplus project, which brought together more than 20 environmental and Earth science research infrastructures into a single community. It provides readers with a systematic overview of the common challenges faced by research infrastructures and how a ‘reference model guided’ engineering approach can be used to achieve greater interoperability among such infrastructures in the environmental and earth sciences. The 20 contributions in this book are structured in 5 parts on the design, development, deployment, operation and use of research infrastructures. Part one provides an overview of the state of the art of research infrastructure and relevant e-Infrastructure technologies, part two discusses the reference model guided engineering approach, the third part presents the software and tools developed for common data management challenges, the fourth part demonstrates the software via several use cases, and the last part discusses the sustainability and future directions

    Virtual Heritage

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    Virtual heritage has been explained as virtual reality applied to cultural heritage, but this definition only scratches the surface of the fascinating applications, tools and challenges of this fast-changing interdisciplinary field. This book provides an accessible but concise edited coverage of the main topics, tools and issues in virtual heritage. Leading international scholars have provided chapters to explain current issues in accuracy and precision; challenges in adopting advanced animation techniques; shows how archaeological learning can be developed in Minecraft; they propose mixed reality is conceptual rather than just technical; they explore how useful Linked Open Data can be for art history; explain how accessible photogrammetry can be but also ethical and practical issues for applying at scale; provide insight into how to provide interaction in museums involving the wider public; and describe issues in evaluating virtual heritage projects not often addressed even in scholarly papers. The book will be of particular interest to students and scholars in museum studies, digital archaeology, heritage studies, architectural history and modelling, virtual environments
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