1,011 research outputs found

    A Survey of Volunteered Open Geo-Knowledge Bases in the Semantic Web

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    Over the past decade, rapid advances in web technologies, coupled with innovative models of spatial data collection and consumption, have generated a robust growth in geo-referenced information, resulting in spatial information overload. Increasing 'geographic intelligence' in traditional text-based information retrieval has become a prominent approach to respond to this issue and to fulfill users' spatial information needs. Numerous efforts in the Semantic Geospatial Web, Volunteered Geographic Information (VGI), and the Linking Open Data initiative have converged in a constellation of open knowledge bases, freely available online. In this article, we survey these open knowledge bases, focusing on their geospatial dimension. Particular attention is devoted to the crucial issue of the quality of geo-knowledge bases, as well as of crowdsourced data. A new knowledge base, the OpenStreetMap Semantic Network, is outlined as our contribution to this area. Research directions in information integration and Geographic Information Retrieval (GIR) are then reviewed, with a critical discussion of their current limitations and future prospects

    Managing contextual information in semantically-driven temporal information systems

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    Context-aware (CA) systems have demonstrated the provision of a robust solution for personalized information delivery in the current content-rich and dynamic information age we live in. They allow software agents to autonomously interact with users by modeling the user’s environment (e.g. profile, location, relevant public information etc.) as dynamically-evolving and interoperable contexts. There is a flurry of research activities in a wide spectrum at context-aware research areas such as managing the user’s profile, context acquisition from external environments, context storage, context representation and interpretation, context service delivery and matching of context attributes to users‘ queries etc. We propose SDCAS, a Semantic-Driven Context Aware System that facilitates public services recommendation to users at temporal location. This paper focuses on information management and service recommendation using semantic technologies, taking into account the challenges of relationship complexity in temporal and contextual information

    Dwelling on ontology - semantic reasoning over topographic maps

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    The thesis builds upon the hypothesis that the spatial arrangement of topographic features, such as buildings, roads and other land cover parcels, indicates how land is used. The aim is to make this kind of high-level semantic information explicit within topographic data. There is an increasing need to share and use data for a wider range of purposes, and to make data more definitive, intelligent and accessible. Unfortunately, we still encounter a gap between low-level data representations and high-level concepts that typify human qualitative spatial reasoning. The thesis adopts an ontological approach to bridge this gap and to derive functional information by using standard reasoning mechanisms offered by logic-based knowledge representation formalisms. It formulates a framework for the processes involved in interpreting land use information from topographic maps. Land use is a high-level abstract concept, but it is also an observable fact intimately tied to geography. By decomposing this relationship, the thesis correlates a one-to-one mapping between high-level conceptualisations established from human knowledge and real world entities represented in the data. Based on a middle-out approach, it develops a conceptual model that incrementally links different levels of detail, and thereby derives coarser, more meaningful descriptions from more detailed ones. The thesis verifies its proposed ideas by implementing an ontology describing the land use ‘residential area’ in the ontology editor ProtĂ©gĂ©. By asserting knowledge about high-level concepts such as types of dwellings, urban blocks and residential districts as well as individuals that link directly to topographic features stored in the database, the reasoner successfully infers instances of the defined classes. Despite current technological limitations, ontologies are a promising way forward in the manner we handle and integrate geographic data, especially with respect to how humans conceptualise geographic space

    Conservation GIS: Ontology and spatial reasoning for commonsense knowledge.

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    Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial Technologies.Geographic information available from multiple sources are moving beyond their local context and widening the semantic difference. The major challenge emerged with ubiquity of geographic information, evolving geospatial technology and location-aware service is to deal with the semantic interoperability. Although the use of ontology aims at capturing shared conceptualization of geospatial information, human perception of world view is not adequately addressed in geospatial ontology. This study proposes ‘Conservation GIS Ontology’ that comprises spatial knowledge of non-expert conservationists in the context of Chitwan National Park, Nepal. The discussion is presented in four parts: exploration of commonsense spatial knowledge about conservation; development of conceptual ontology to conceptualize domain knowledge; formal representation of conceptualization in Web Ontology Language (OWL); and quality assessment of the ontology development tasks. Elicitation of commonsense spatial knowledge is performed with the notion of cognitive view of semantic. Emphasis is given to investigate the observation of wildlife movement and habitat change scenarios. Conceptualization is carried out by providing the foundation of the top-level ontology- ‘DOLCE’ and geospatial ontologies. ProtĂ©gĂ© 4.1 ontology editor is employed for ontology engineering tasks. Quality assessment is accomplished based on the intrinsic approach of ontology evaluation.(...

    Assessing the quality of geospatial linked data – experiences from Ordnance Survey Ireland (OSi)

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    Ordnance Survey Ireland (OSi) is Ireland’s national mapping agency that is responsible for the digitisation of the island’s infrastructure in terms of mapping. Generating data from various sensors (e.g. spatial sensors), OSi build its knowledge in the Prime2 framework, a subset of which is transformed into geo-Linked Data. In this paper we discuss how the quality of the generated sematic data fares against datasets in the LOD cloud. We set up Luzzu, a scalable Linked Data quality assessment framework, in the OSi pipeline to continuously assess produced data in order to tackle any quality problems prior to publishing

    Interacting with ontologies and linked data through controlled natural languages and dialogues

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    This paper describes a suite of tools developed at the University of Leeds which aim to make it easier for domain experts to be involved in the creation and use of ontologies. The paper summarises the main features of the tools and gives a short summary of our evaluations and experiences using the tools with domain experts

    Capturing place semantics on the GeoSocial web

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