Cristiano Fugazza

RITMARE: Semantics-aware Harmonisation of Data in Italian Marine Research

Abstract RITMARE is a Flagship Project by the Italian Ministero dell’Istruzione, dell’Universita e della Ricerca (MIUR) and coordinated by the National Research Council (CNR). It aims at the interdisciplinary integration of national marine research. In pursuing a Linked Open Data (LOD) vocation, the RITMARE sub-project 7 is building the necessary domain-related data structures by leveraging existing RDF-based schemata and sources. These data structures are grounding semantics-aware profiling of end users, data providers, and resources. The goal is designing a flexible infrastructure that adapts to the audiences specificities.

Sensor metadata blueprints and computer-aided editing for disciplined SensorML

The need for continuous, accurate, and comprehensive environmental knowledge has led to an increase in sensor observation systems and networks. The Sensor Web Enablement (SWE) initiative has been promoted by the Open Geospatial Consortium (OGC) to foster interoperability among sensor systems. The provision of metadata according to the prescribed SensorML schema is a key component for achieving this and nevertheless availability of correct and exhaustive metadata cannot be taken for granted. On the one hand, it is awkward for users to provide sensor metadata because of the lack in user-oriented, dedicated tools. On the other, the specification of invariant information for a given sensor category or model (e.g., observed properties and units of measurement, manufacturer information, etc.), can be labor- and timeconsuming. Moreover, the provision of these details is error prone and subjective, i.e., may differ greatly across distinct descriptions for the same system. We provide a user-friendly, template-driven metadata authoring tool composed of a backend web service and an HTML5/javascript client. This results in a form-based user interface that conceals the high complexity of the underlying format. This tool also allows for plugging in external data sources providing authoritative definitions for the aforementioned invariant information. Leveraging these functionalities, we compiled a set of SensorML profiles, that is, sensor metadata blueprints allowing end users to focus only on the metadata items that are related to their specific deployment. The natural extension of this scenario is the involvement of end users and sensor manufacturers in the crowd-sourced evolution of this collection of prototypes. We describe the components and workflow of our framework for computer-aided management of sensor metadata.

A Holistic, Semantics-aware Approach to Spatial Data Infrastructures

We present a novel approach to the management of Spatial Data Infrastrutures that leverages semantics-aware context information to model the distinct aspects involved in the management of spatial data. RDF-based schemata are employed for encoding information on the user community, the terminologies in use in a specific research domain, gazetteer information representing the physical landscape hosting data and, last but not least, spatial resource metadata. The data structures are then interconnected to enable seamless exploitation for metadata creation and resource discovery, which we demonstrate through a worked-out example of SPARQL query on RDF graph data. The methodology is being applied by by the National Research Council (CNR) of Italy to support creation of a distributed infrastructure for marine data in the context of the RITMARE Flagship Project.

The RITMARE Starter Kit bottom-up capacity building for geospatial data providers

Capacity building by data providers is a fundamental task in the creation of a decentralized Spatial Data Infrastructure. This challenge has been tackled in the RITMARE Flagship Project by providing the Starter Kit, a comprehensive set of domain-oriented software components that exposes standard services for the management of geospatial information. We report on the characteristics of this toolkit, developed by the National Research Council of Italy (CNR), particularly with regard to the underlying service-oriented architecture and the novel semantics-aware methodology that is proposed for metadata editing.

Streamlining geospatial metadata in the Semantic Web

In the geospatial realm, data annotation and discovery rely on a number of ad-hoc formats and protocols. These have been created to enable domain-specific use cases generalized search is not feasible for. Metadata are at the heart of the discovery process and nevertheless they are often neglected or encoded in formats that either are not aimed at efficient retrieval of resources or are plainly outdated. Particularly, the quantum leap represented by the Linked Open Data (LOD) movement did not induce so far a consistent, interlinked baseline in the geospatial domain. In a nutshell, datasets, scientific literature related to them, and ultimately the researchers behind these products are only loosely connected; the corresponding metadata intelligible only to humans, duplicated on different systems, seldom consistently. Instead, our workflow for metadata management envisages i) editing via customizable web- based forms, ii) encoding of records in any XML application profile, iii) translation into RDF (involving the semantic lift of metadata records), and finally iv) storage of the metadata as RDF and back-translation into the original XML format with added semantics-aware features. Phase iii) hinges on relating resource metadata to RDF data structures that represent keywords from code lists and controlled vocabularies, toponyms, researchers, institutes, and virtually any description one can retrieve (or directly publish) in the LOD Cloud. In the context of a distributed Spatial Data Infrastructure (SDI) built on free and open-source software, we detail phases iii) and iv) of our workflow for the semantics-aware management of geospatial metadata.

Web-Scale Normalization of Geospatial Metadata Based on Semantics-Aware Data Sources

Geospatial metadata are largely denormalized inasmuch as resource descriptions typically accommodate property values as plain text. Hence, it is not possible to bring multiple references to the same entity (say, a keyword from a controlled vocabulary) under the same umbrella. This practice is ultimately the main source for the heterogeneities in metadata descriptions by which geospatial discovery is hampered. In this paper, we elaborate on ex-post semantic augmentation of metadata, a technique generally referred to as semantic lift, which complements our previous research on semantic characterization of metadata via transparent association of uniform resource identifiers with metadata items at editing time. The latter is accomplished by means of a template-based metadata editor that can be tailored to any XML-based metadata schema. By repurposing the template language previously defined for metadata editing, we broaden the expressiveness of the former and integrate heterogeneous, XML-based resource descriptions in our semantics-aware metadata management workflow. URI-based indirection in metadata provision not only entails normalization of individual information items and allows one to overcome the aforementioned heterogeneities, but also elicits decentralized, multi-tenanted management of metadata.

VGI Imperfection in Citizen Science Projects and Its Representation and Retrieval Based on Fuzzy Ontologies and Level-Based Approximate Reasoning

The chapter investigates the kinds of imperfection affecting Volunteer Geographic Information (VGI) created by users eager to participate in some citizen science project. An approach based on the use of fuzzy domain ontologies and level-based approximate reasoning is suggested to represent and manage both the uncertainty of volunteers when describing their observations and the vagueness of ill-defined domain knowledge. This way one can model more reliable smart applications for creating VGI as well as can design less ambiguous spatial data infrastructures (SDIs) for sharing VGI with final stakeholders.