78 research outputs found

    VALIDATION OF GEOGRAPHICAL DATASETS AGAINST SPATIAL CONSTRAINTS AT CONCEPTUAL LEVEL

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    A template-based approach for the specification of 3D topological constraints

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    Several different models have been defined in literature for the definition of 3D scenes that include a geometrical representation of objects together with a semantical classification of them. Such semantical characterization encapsulates important details about the object properties and behavior and often includes spatial relations that are defined only implicitly or through natural language, such as \u201can external access shall be in touch with the building only when it is classified as a direct access\u201d. The problem of ensuring the coherence between geometric and semantic information is well known in literature. Many attempts exist which try to extent the OCL to allow the representation of spatial integrity constraints in an UML model. However, this approach requires a deep knowledge of the OCL formalism and the implementation of ad-hoc procedures to validate the constraints specified at conceptual level. Therefore, a new approach is needed that helps designers to define complex OCL constraints and at the same time allows the automatic generation of the code to test them on a given dataset. The aim of this paper is to propose a set of predefined templates to express on the classes of an UML data model, a family of 3D spatial integrity constraints based on topological relations; all this without requiring the knowledge of any formal language by domain experts and supporting their automatic translation into validation procedures

    The Archaeological Urban Information System of Verona: an approach to interoperability through standard-based conceptual modelling

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    Since 2011 the Archaeological Geographical Information System of Verona, SITAVR, has been implemented based on the existing and well-consolidated Archaeological Information Systemof Rome, SITAR, developed since 2008. The main objective of the two projects is collecting information about the archaeological findings regarding the two Italian urban centres with the aim to support a complete archaeological analysis and allow for easy data reuse. The purpose of this research is twofold: (i) archaeological studies, aimed to collect data and contents, and (ii) information systems applied to cultural heritage, aimed to organize, use and preserve the data on the basis of the innovations related to methodologies, technologies and standards. In this regard, the first step in SITAVR project was to create a domain model of archaeological data, by applying standard methodology for producing an abstract conceptual schema. Next steps were the definition of web services and a common format for data exchange; further in this direction was the creation of a mapping between this model and other international standards. The definition of the conceptual schema and the metadata, the common format for data exchange and the mapping on international standards have supported and encouraged the cooperation between SITAVR and SITAR projects. Moreover also some practical tests of interoperability between the two systems have been performed, thus demonstrating the effectiveness of the proposed approach. In particular, an experiment regarding the integrated execution of some queries on the two systems (funerary contexts and the road network of the two towns) was successfully implemented. In conclusion, our work further demonstrates that interoperability requires an initial large investment of resources, but allows to achieve results in terms of data analysis that by means of non-integrated systems cannot be easily accomplished

    An Interoperable Spatio-Temporal Model for Archaeological Data Based on ISO Standard 19100

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    Archaeological data are characterized by both spatial and temporal dimensions that are often related to each other and are of particular interest during the interpretation process. For this reason, several attempts have been performed in recent years in order to develop a GIS tailored for archaeological data. However, despite the increasing use of information technologies in the archaeological domain, the actual situation is that any agency or research group independently develops its own local database and management application which is isolated from the others. Conversely, the sharing of information and the cooperation between different archaeological agencies or research groups can be particularly useful in order to support the interpretation process by using data discovered in similar situations w.r.t. spatio-temporal or thematic aspects. In the geographical domain, the INSPIRE initiative of European Union tries to support the development of a Spatial Data Infrastructure (SDI) through which several organizations, like public bodies or private companies, with overlapping goals can share data, resources, tools and competencies in an effective way. The aim of this paper is to lay the basis for the development of an Archaeological SDI starting from the experience acquired during the collaboration among several Italian organizations. In particular, the paper proposes a spatio-temporal conceptual model for archaeological data based on the ISO Standards of the 19100 family and promotes the use of the GeoUML methodology in order to put into practice such interoperability. The GeoUML methodology and tools have been enhanced in order to suite the archaeological domain and to automatically produce several useful documents, configuration files and codebase starting from the conceptual specification. The applicability of the spatio-temporal conceptual model and the usefulness of the produced tools have been tested in three different Italian contexts: Rome, Verona and Isola della Scala

    Data State of Play - Compliance Testing and Interoperability Checking

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    The document provides an inventory of existing solutions for compliance testing and interoperability checking for data taking into account the draft INSPIRE data specifications conceptual model (D2.5), the first draft of the INSPIRE Methodology for the development of data specifications (D2.6) and the first draft of the data Specifications Guidelines for the encoding of spatial data (D2.7). Even if the emphasis is on spatial and geographical data, the document investigates applicable solutions outside the geographical Information System domain, with a particular attention paid to checking compliance with Âżapplication schemasÂż as defined in the previously mentioned documents.JRC.H.6-Spatial data infrastructure

    Spatial Integrity Constraints in 3D City Models: from Conceptual Definition to SQL Implementation

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    Several different models have been defined in literature for the definition of 3D city models, from CityGML to Inspire (Annex 3 - Buildings). Such models include a geometrical representation of features together with a semantical classification of them. The semantical characterization of objects encapsulates important meaning and spatial relations which are defined only implicitly or through natural language, such as buildings shall be disjoint or in touch, or a window surface shall be contained in the building boundary. The problem of ensuring the coherence between geometric and semantic information is well known in literature. Many attempts exist which try to extent the OCL language in order to represent spatial constraints for an UML model. However, this approach requires a deep knowledge of the OCL language and the implementation of ad-hoc procedures for the validation of constraints defined at conceptual level. The aim of this paper is the development of a set of templates for expressing spatial 3D constraints between features which does not require any particular knowledge of a formal language. Moreover, the constraints instantiated from these templates can be automatically translated into validation SQL queries, without the need for ad-hoc implementations

    Hydrogeological data modelling in groundwater studies

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    Managing, handling, exchanging and accessing hydrogeological information depend mainly on the applied hydrogeological data models, which differ between institutions and acrosscountries. Growing interest in hydrogeological information diffusion, combined with a need for information availability, require the convergence of hydrogeological data models. Modelconvergence makes hydrogeological information accessible to multiple institutions, universities, administration, water suppliers, and research organisations, at different levels: from the local level (on-site measurement teams), to national and international institutions dealing with water resources management. Furthermore, because hydrogeological studies are complex, they require a large variety of high-quality hydrogeological data with appropriatemetadata in clearly designed and coherent structures.To respond to the requirement of model convergence, easy information exchange and hydrogeological completeness, new data models have been developed, using two different methodologies. At local-regional level, the HydroCube model has been developed for the Walloon Region in Belgium. This logical data model uses entity-relationship diagrams and ithas been implemented in the MS Access environment, further enriched with a fully functional user-interface. The HydroCube model presents an innovative holistic “project-based” approach, which covers a full set of hydrogeological concepts and features, allowing for effective hydrogeological project management. This approach enables to store data about theproject localisation, hydrogeological equipment, related observations and measurements. Furthermore, topological relationships facilitate management of spatially associated data. Finally, the model focuses on specialized hydrogeological field experiments, such as pumping tests and tracer tests.At the international level, a new hydrogeological data model has been developed which guarantees hydrogeological information availability in one standard format in the scope of the FP6 project GABARDINE (“Groundwater Artificial recharge Based on Alternative sources of wateR: aDvanced Integrated technologies and management”). The model has beenimplemented in the ArcGIS environment, as a Geospatial Database for a decision support system. The GABARDINE Geospatial Database uses advantages of object-oriented modelling (UML), it follows standards for geoscientific information exchange (ISO/TC211 and OGC), and it is compliant with the recommendations from the European Geospatial Information Working Group.Finally, these two developed models have been tested with hydrogeological field data on different informatics platforms: from MS Access, through a proprietary ArcGIS environment, to the open source, free Web2GIS on-line application. They have also contributed to the development of the GroundWater Markup Language (GWML) Canadian exchange standard, compliant with Geographic Markup Language (GML). GWML has the potential of becoming an international HydroGeology Markup Language (HgML) standard with a strong and continuous support from the hydrogeological community

    Architectures and Standards for Spatial Data Infrastructures and Digital Government: European Union Location Framework Guidelines

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    This document provides an overview of the architecture(s) and standards for Spatial Data Infrastructures (SDI) and Digital Government. The document describes the different viewpoints according to the Reference Model for Open and Distributed Processing (RM-ODP) which is often used in both the SDI and e-Government worlds: the enterprise viewpoint, the engineering viewpoint, the information viewpoint, the computational viewpoint and the technological viewpoint. The document not only describes these viewpoints with regard to SDI and e-Government implementations, but also how the architecture(s) and standards of SDI and e-Government relate. It indicates which standards and tools can be used and provides examples of implementations in different areas, such as process modelling, metadata, data and services. In addition, the annex provides an overview of the most commonly used standards and technologies for SDI and e-Government.JRC.B.6-Digital Econom

    Fachlich erweiterbare 3D-Stadtmodelle – Management, Visualisierung und Interaktion

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    Domain-extendable semantic 3D city models are complex mappings and inventories of the urban environment which can be utilized as an integrative information backbone to facilitate a range of application fields like urban planning, environmental simulations, disaster management, and energy assessment. Today, more and more countries and cities worldwide are creating their own 3D city models based on the CityGML specification which is an international standard issued by the Open Geospatial Consortium (OGC) to provide an open data model and XML-based format for describing the relevant urban objects with regards to their 3D geometry, topology, semantics, and appearance. It especially provides a flexible and systematic extension mechanism called “Application Domain Extension (ADE)” which allows third parties to dynamically extend the existing CityGML definitions with additional information models from different application domains for representing the extended or newly introduced geographic object types within a common framework. However, due to the consequent large size and high model complexity, the practical utilization of country-wide CityGML datasets has posed a tremendous challenge regarding the setup of an extensive application system to support the efficient data storage, analysis, management, interaction, and visualization. These requirements have been partly solved by the existing free 3D geo-database solution called ‘3D City Database (3DCityDB)’ which offers a rich set of functionalities for dealing with standard CityGML data models, but lacked the support for CityGML ADEs. The key motivation of this thesis is to develop a reliable approach for extending the existing database solution to support the efficient management, visualization, and interaction of large geospatial data elements of arbitrary CityGML ADEs. Emphasis is first placed on answering the question of how to dynamically extend the relational database schema by parsing and interpreting the XML schema files of the ADE and dynamically create new database tables accordingly. Based on a comprehensive survey of the related work, a new graph-based framework has been proposed which uses typed and attributed graphs for semantically representing the object-oriented data models of CityGML ADEs and utilizes graph transformation systems to automatically generate compact table structures extending the 3DCityDB. The transformation process is performed by applying a series of fine-grained graph transformation rules which allow users to declaratively describe the complex mapping rules including the optimization concepts that are employed in the development of the 3DCityDB database schema. The second major contribution of this thesis is the development of a new multi-level system which can serve as a complete and integrative platform for facilitating the various analysis, simulation, and modification operations on the complex-structured 3D city models based on CityGML and 3DCityDB. It introduces an additional application level based on a so-called ‘app-concept’ that allows for constructing a light-weight web application to reach a good balance between the high data model complexity and the specific application requirements of the end users. Each application can be easily built on top of a developed 3D web client whose functionalities go beyond the efficient 3D geo-visualization and interactive exploration, and also allows for performing collaborative modifications and analysis of 3D city models by taking advantage of the Cloud Computing technology. This multi-level system along with the extended 3DCityDB have been successfully utilized and evaluated by many practical projects.Fachlich erweiterbare semantische 3D-Stadtmodelle sind komplexe Abbildungen und DatenbestĂ€nde der stĂ€dtischen Umgebung, die als ein integratives InformationsrĂŒckgrat genutzt werden können, um eine Reihe von Anwendungsfeldern wie z. B. Stadtplanung, Umweltsimulationen, Katastrophenmanagement und Energiebewertung zu ermöglichen. Heute schaffen immer mehr LĂ€nder und StĂ€dte weltweit ihre eigenen 3D-Stadtmodelle auf Basis des internationalen Standards CityGML des Open Geospatial Consortium (OGC), um ein offenes Datenmodell und ein XML-basiertes Format zur Beschreibung der relevanten Stadtobjekte in Bezug auf ihre 3D-Geometrien, Topologien, Semantik und Erscheinungen zur VerfĂŒgung zu stellen. Es bietet insbesondere einen flexiblen und systematischen Erweiterungsmechanismus namens „Application Domain Extension“ (ADE), der es Dritten ermöglicht, die bestehenden CityGML-Definitionen mit zusĂ€tzlichen Informationsmodellen aus verschiedenen AnwendungsdomĂ€nen dynamisch zu erweitern, um die erweiterten oder neu eingefĂŒhrten Stadtobjekt-Typen innerhalb eines gemeinsamen Framework zu reprĂ€sentieren. Aufgrund der konsequent großen Datenmenge und hohen ModellkomplexitĂ€t bei der praktischen Nutzung der landesweiten CityGML-DatensĂ€tze wurden jedoch enorme Anforderungen an den Aufbau eines umfangreichen Anwendungssystems zur UnterstĂŒtzung der effizienten Speicherung, Analyse, Verwaltung, Interaktion und Visualisierung der Daten gestellt. Die bestehende kostenlose 3D-Geodatenbank-Lösung „3D City Database“ (3DCityDB) entsprach bereits teilweise diesen Anforderungen, indem sie zwar eine umfangreiche FunktionalitĂ€t fĂŒr den Umgang mit den Standard-CityGML-Datenmodellen, jedoch keine UnterstĂŒtzung fĂŒr CityGML-ADEs bietet. Die SchlĂŒsselmotivation fĂŒr diese Arbeit ist es, einen zuverlĂ€ssigen Ansatz zur Erweiterung der bestehenden Datenbanklösung zu entwickeln, um das effiziente Management, die Visualisierung und Interaktion großer DatensĂ€tze beliebiger CityGML-ADEs zu unterstĂŒtzen. Der Schwerpunkt liegt zunĂ€chst auf der Beantwortung der SchlĂŒsselfrage, wie man das relationale Datenbankschema dynamisch erweitern kann, indem die XML-Schemadateien der ADE analysiert und interpretiert und anschließend dem entsprechende neue Datenbanktabellen erzeugt werden. Auf Grundlage einer umfassenden Studie verwandter Arbeiten wurde ein neues graphbasiertes Framework entwickelt, das die typisierten und attributierten Graphen zur semantischen Darstellung der objektorientierten Datenmodelle von CityGML-ADEs verwendet und anschließend Graphersetzungssysteme nutzt, um eine kompakte Tabellenstruktur zur Erweiterung der 3DCityDB zu generieren. Der Transformationsprozess wird durch die Anwendung einer Reihe feingranularer Graphersetzungsregeln durchgefĂŒhrt, die es Benutzern ermöglicht, die komplexen Mapping-Regeln einschließlich der Optimierungskonzepte aus der Entwicklung des 3DCityDB-Datenbankschemas deklarativ zu formalisieren. Der zweite wesentliche Beitrag dieser Arbeit ist die Entwicklung eines neuen mehrstufigen Systemkonzepts, das auf CityGML und 3DCityDB basiert und gleichzeitig als eine komplette und integrative Plattform zur Erleichterung der Analyse, Simulationen und Modifikationen der komplex strukturierten 3D-Stadtmodelle dienen kann. Das Systemkonzept enthĂ€lt eine zusĂ€tzliche Anwendungsebene, die auf einem sogenannten „App-Konzept“ basiert, das es ermöglicht, eine leichtgewichtige Applikation bereitzustellen, die eine gute Balance zwischen der hohen ModellkomplexitĂ€t und den spezifischen Anwendungsanforderungen der Endbenutzer erreicht. Jede Applikation lĂ€sst sich ganz einfach mittels eines bereits entwickelten 3D-Webclients aufbauen, dessen FunktionalitĂ€ten ĂŒber die effiziente 3D-Geo-Visualisierung und interaktive Exploration hinausgehen und auch die DurchfĂŒhrung kollaborativer Modifikationen und Analysen von 3D-Stadtmodellen mit Hilfe von der Cloud-Computing-Technologie ermöglichen. Dieses mehrstufige System zusammen mit dem erweiterten 3DCityDB wurde erfolgreich in vielen praktischen Projekten genutzt und bewertet
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