The Atlas of Paths project has two main goals: (i) the creation and implementation of an ontology network representing information contained in the MiBACT's Atlante dei Cammini d'Italia and de ning the concept of path; (ii) the design of a prototype for a modular software platform allowing the production of the Atlante Linked Open Data as foreseen in its ontological formalization.
to improve the interoperability between Italian public administrations by de ning a shared conceptualization of data and promoting the adoption of Open Data. For modeling AoP we bene t from reusing some ontological modules from OntoPiA, namely: L0, which de nes top-level concepts (e.g. Event, Object etc.); CVL, as the ontology on addresses and places; POI, on points of interests; ACCO, on accommodation facilities; TI, on the temporal dimension of concepts; MU, on the measurement units. 2
How to describe a Path? This theoretical question summarizes 25 competency
questions (CQs) - a common tool for de ning modeling requirements to be
satis ed by a ontology [
The CQs led us to design two networked ontological modules: (i) Route6, which is a general conceptualization for supporting the domain ontology; (ii) Atlas of Paths7, which de nes more speci c concepts imported by the supporting ontology. 2.1
Taking into account the modelling of Semantic Trajectories [
The class :Route is de ned as an intersection of L0:Sequence, which represents a sequence of ordered objects, and L0:Description, which represents socially constructed objects (i.e. texts, values, categories, relationships, contexts) used to describe something else in a structured way. In addition, an instance of :Route can be connected by means of CLV:hasGeometry to an instance of CLV:Geometry, which provides the possibility of georeferencing a spatial object through CLV:lat (latitude) and CLV:long (longitude). The object property (op) :crosses allows to connect a :Route to any object having a spatial representation, so that it is possible to assert that a pathway crosses a certain area.
The class :Stage represents the elements of a :Route. Stages ordering of a route allows to identify the direct successor and predecessor of a stage through L0:directlyFollows and L0:directlyPrecedes. Georeferencing can also be associated with a stage by reusing the CLV module.
The class :TripPlan represents a travel plan for a speci c route by means of :hasRoute. It is modeled by associating a certain trip time with the traveled route through :hasEstimatedDuration. In addition, a trip plan can be split into sub-trip plans through :hasSubTripPlan.
Atlas Of Paths: a Formal Ontology of Historical Pathways in Italy
The concepts de ned in the Route module are specialized in AoP, as depicted in Figure 1.
The class :Pathway, de ned as a subclass of Route:Route, describes a pathway in its physical meaning. E.g., since a path to be included in the Atlante must be paved in asphalt for a maximum of 40% of its total length, the :QuantifiedPathwayPaving represents the n-ary relation able to quantify the MU:maxPercentage of a :Pathway (op :forPathway) with a speci c :Paving (op :withPaving), represented as the instance :asphalt. In Manchester Syntax: :Pathway subClassOf inverse(:forPathway) only ((:withPaving value :asphalt) and
(MU:maxPercentage exactly 1 xsd:double[<"40.0"8sd:double])). The class :PathStage, a subClassOf Route:Stage, is associated with :SupportService, representing any walker support services, de ned by :hasService Type. A path stage is also associated with some POI:PointOfInterest, e.g. hotel facilities, represented by ACCO:Accommodation, and catering activities, represented by :Restaurant.
The class :PathPlan, a subClassOf Route:TripPlan, is a n-ary relation with three arguments: (i) :TravelingMethod which can be either on foot, on horseback, or by bicycle; (ii) TI:TemporalEntity, which speci es which period of the year is most suitable for planning the journey, and linked to a :PathPlan by means of :bestWhen.
The class :Path is the main and peculiar one of the Atlante domain. A :Path can be associated with one or more :Pathway, through Route:hasRoute. In addition, its sub-properties Route:hasPreRoute, Route:hasAltRoute and Route:hasDeviation allow to associate a :Path to a :Pathway so that it can be identi ed as the main path, an alternative or a deviation, respectively. These arguments contribute to strongly de ne the concept of :Path, which implies the possibility of choosing at each :PathStage to change the :Pathway. 2.3
We designed a modular software platform8 for supporting data-entry by users proposing new Italian paths to be evaluated by the MiBACT Committee. This platform prototype provides a series of input forms that guide users in lling the necessary information to describe a path as foreseen in its ontological formalization. It has been implemented according to the Model-View-Controller pattern. The use of this pattern allows to implement: (i) the Model as the ontologies themselves; (ii) the View as the input forms; (iii) the Controller as a software module (implemented in PHP) to generate a pipeline of input forms based on the logical representation de ned in the ontology.
The AoP project has brought the following results: (a) a formal ontology de ning the concept of path; (b) a prototype for a modular software platform to perform a LOD production consistent with the AoP ontology.
In addition to the progressive LOD production by means of the data-entry, it will be possible to link AoP with other datasets already available as LOD, such as Cultural-ON9, ArCo10 and FOOD11 representing Italian assets of cultural heritage and food products in those areas that are crossed by a given path.
10 https://w3id.org/arco 11 http://etna.istc.cnr.it/food/