Jean Brodeur

Modelling geospatial application databases using UML-based repositories aligned with international standards in geomatics

This paper presents the result of recent work on the use of geospatial repositories to store the conceptual content of object oriented application database schemas and dictionaries aligned with international standards in geographic information (ISO/TC 211 and OGC). According to software engineering and database concepts, a geospatial repository can be defined as a collection of (meta) data structured in a manner to provide information about the semantics, geometry, temporality, and the integrity constraint of data stored in a geospatial database. For the last 6 years, ISO/TC 211 and OGC have been developing standards about geographic information to enable access and interoperability of geographic information; parts of these standards impact directly on geospatial repositories. Our work demonstrates that it is possible to develop a geospatial repository aligned with these standards and to implement it in a UML-based visual modelling tool.

Revisiting the Concept of Geospatial Data Interoperability within the Scope of Human Communication Processes

Geospatial data interoperability has been the target of major efforts by standardization bodies (e.g. OGC, ISO/TC 211) and the research community since the beginning of the 1990s. It is seen as a solution for sharing and integrating geospatial data, more specifically to solve the syntactic, schematic, and semantic as well as the spatial and temporal heterogeneities between various representations of real-world phenomena. A few models have been proposed to automatically overcome heterogeneity of geospatial data and, as a result, increase the interoperability of geospatial data. However, the addition of a conceptual framework of geospatial data interoperability would contribute to understanding geospatial data interoperability, the appreciation of where existing contributions specifically apply, and would foster new contributions. In this paper, we revisit the concept of geospatial data interoperability within the broader scope of human communication and cognition. Human communication appears to be a rich framework since humans interoperate more easily than computers do. Accordingly, we present a conceptual framework of geospatial data interoperability that is broader in scope than existing frameworks and supported by several practical examples. An ontology of geospatial data interoperability is also introduced in order to refine the description of the conceptual framework. In such a communication-based framework, the notions of concept,

A spatial data infrastructure model from the computational viewpoint

The Commission on Geoinformation Infrastructures and Standards of the International Cartographic Association (ICA) is working on defining models of spatial data infrastructures (SDIs). SDI models from the enterprise and information viewpoints of the Reference Model for Open Distributed Processing (RM-ODP) have already been presented. Our model from the computational viewpoint identifies the main computational objects of an SDI and their interfaces, which are modelled using Unified Modelling Language (UML) component diagrams. Presented here is the first comprehensive SDI model from the computational viewpoint, which enhances the understanding of the computational objects and their interactions in an SDI. This viewpoint complements the previous two and together, the three viewpoints contribute towards a more holistic interpretation of an SDI, which is independent of specific SDI legislation, technology and implementations. For the computational viewpoint, we identified six computational objects, SDI Registry, SDI Data, SDI Processing, SDI Application, SDI Portrayal and SDI Management, and their provided and required interfaces. We describe the interactions of the computational objects in stakeholder activities and the roles they play in the different processes of SDI development and use, which we identified as Initiation, Creation, Management, Manipulation, Access, Processing, Evaluation and Liaison. Two tables summarise the SDI services that are provided by computational objects for stakeholder activities and SDI processes.

Mapping between dynamic ontologies in support of geospatial data integration for disaster management

The effective management of disasters requires providing relevant and right information to the concerned decision makers. By its nature, disaster management involves multiple actors and organizations, potentially implying a significant volume of geospatial data coming from heterogeneous and autonomous geospatial data sources. Integration of these data sources is difficult not only because of the semantic heterogeneity of data but also because of the dynamic nature of the reality that is studied. The dynamic aspect of the reality has a direct impact in the conceptualisation of such a reality by adding different event categories to the domain ontology, thus making more complicated to apply existing methods for the mapping and integration of ontologies. In this article, we highlight some problems of heterogeneity that complicate the integration of ontologies composed of objects and events concepts; we also propose a similarity model designed to support mapping of these ontologies.

A conceptual framework to support semantic interoperability of geospatial datacubes

Today, we observe a wide use of geospatial databases that are implemented in many forms (e.g. transactional centralized systems, distributed databases, multidimensional datacubes). Among those possibilities, the multidimensional datacube is more appropriate to support interactive analysis and to guide the organizations strategic decisions, especially when different epochs and levels of information granularity are involved. However, one may need to use several geospatial multidimensional datacubes which may be heterogeneous in design or content. Overcoming the heterogeneity problems in a manner that is transparent to users has been the principal aim of interoperability for the last fifteen years. In spite of successful initiatives and widespread use of standards, todays solutions do not address yet geospatial datacubes. This paper aims at describing the interoperability of geospatial datacubes, defining the semantic heterogeneity problems that may occur when using different geospatial datacubes, and proposing a conceptual framework to support semantic interoperability of these datacubes.

A geosemantic proximity-based prototype for the interoperability of geospatial data

Abstract The research agenda related to the interoperability of geospatial data is influenced by the increased accessibility of geospatial databases on the Internet, as well as their sharing and their integration. Although it is now possible to get and use geospatial data independently of their syntax and structure, it is still difficult for users to find the exact data they need as long as they do not know the precise vocabulary used by the organizations supporting geospatial databases. It is now a necessity to take into consideration the semantics of geospatial data to enable its full interoperability. To this end, we designed a new conceptual framework for geospatial data interoperability and introduced the notion of geosemantic proximity based on human communication and cognition paradigms. This paper reviews this framework and the notion of geosemantic proximity. It also presents the GsP Prototype, which demonstrates the relevance of our framework and of the notion of geosemantic proximity for geospatial data interoperability. More specifically, we describe the architecture of the GsP Prototype, its implementation, and tests that have been conducted.

SIM-NET: A View-Based Semantic Similarity Model for Ad Hoc Networks of Geospatial Databases

Semantic similarity is a fundamental notion in GIScience for achieving semantic interoperability among geospatial data. Until now, several semantic similarity models have been proposed; however, few of these models address the issues related to the assessment of semantic similarity in ad hoc networks. Also, several models are based on a definition of concepts where features are independent, an assumption that reduces the richness of the geospatial concept representation. This article presents the conceptual basis for Sim-Net, a novel semantic similarity model for ad hoc networks based on Description Logics (DL). Sim-Net is based on the multi-view paradigm. This paradigm is used to include inferential knowledge in semantic similarity, that is, the knowledge about implicit dependencies between features of concepts. In Sim-Net, assessing semantic similarity relies on the notions of Semantic Reference Systems and Formal Concept Analysis (FCA), which are combined to establish a common semantic reference frame for ontologies of the ad hoc network called the view lattice. The Sim-Net semantic similarity measure distinguishes concepts that belong to different or similar domains and takes into account the neighbours of a concept in the network. An application example is used to show the positive impact of the properties of Sim-Net.

On languages for the specification of integrity constraints in spatial conceptual models

This paper intends to classify, review, and compare the existing languages for the specification of spatial integrity constraints at the conceptual level. We classify these languages into natural, visual, first-order logic, and hybrid and review their syntax and semantics. We compare these language categories based on expressiveness and pragmatics qualities. The results of this study show that controlled natural languages and natural hybrid languages with pictograms are good candidates for expressing spatial integrity constraints at the conceptual level of spatial databases. At the end, we identify new research challenges that should be addressed in this domain in order to facilitate spatial integrity constraint specification and representation.

Formal classification of integrity constraints in spatiotemporal database applications

Imposing integrity constraints is an efficient way to improve data quality in databases. Effective imposition of integrity constraints requires their precise distinction and specification. Despite a few efforts for enhancing the distinction and specification of the integrity constraints in spatial and spatiotemporal databases by their classifications, these classifications fail to precisely distinguish between inherently dissimilar integrity constraints. Furthermore, the existing classifications provide imprecise definitions for the classes of integrity constraints. Such shortcomings explain why still diverse terms are used to refer to a same spatial integrity constraint. In this paper, we propose a formal and more exhaustive classification of the integrity constraints in spatiotemporal databases relying on their nature with respect to space, time, and themes. Moreover, a terminology for the integrity constraints of spatiotemporal databases is presented. Finally, we discuss the advantages of the proposed classification in the specification of integrity constraints.

Geosemantic Interoperability and the Geospatial Semantic Web

This chapter describes what is meant by semantic interoperability of geographic information, the elements involved in semantic interoperability of geographic information, and how semantic interoperability of geographic information has been addressed in spatial data infrastructures (SDIs), standards, and in the Semantic Web. It is formed of ten sections. Semantics is a term used frequently in many contexts. Section 15.2 is dedicated to the description of semantics. Cognition is an area of study about the abstraction of phenomena by human beings. It is significantly related to semantics. Section 15.3 introduces basic notions of cognition related to semantics. Ontology is a well-grounded notion in the study of semantic interoperability and in the Semantic Web. Section 15.4 explains what ontology is about. This will lead to the description, in Sect. 15.5, of semantic interoperability in the context of geographic information, i.e., geosemantic interoperability. A spatial data infrastructure is the typical way in which interoperability of geographic information is implemented. Section 15.6 addresses geosemantic interoperability with respect to spatial data infrastructures. Standards underpin interoperability for geographic information and spatial data infrastructures. Section 15.7 provides an overview of the current contribution of standards bodies with respect to geosemantic interoperability. The Semantic Web makes an important contribution to semantic interoperability. Section 15.8 gives an account of the Semantic Web and its development. The Geospatial Semantic Web brings together the effort of geosemantic interoperability with the effort of the Semantic Web, as presented in Sect. 15.9. Section 15.10 provides concluding remarks on the chapter.