=Paper=
{{Paper
|id=None
|storemode=property
|title=Using Events from UFO-B in an Ontology Collaborative Construction Environment
|pdfUrl=https://ceur-ws.org/Vol-938/ontobras-most2012_paper32.pdf
|volume=Vol-938
|dblpUrl=https://dblp.org/rec/conf/ontobras/RosaCTA12
}}
==Using Events from UFO-B in an Ontology Collaborative Construction Environment==
https://ceur-ws.org/Vol-938/ontobras-most2012_paper32.pdf
Using Events from UFO-B in an Ontology Collaborative
Construction Environment
Douglas Eduardo Rosa1 , Joel Luis Carbonera1 , Gabriel M. Torres1 , Mara Abel1
1
Institute of Informatics – Universidade Federal do Rio Grande do Sul (UFRGS)
Caixa Postal 15.064 – 91.501-970 – Porto Alegre – RS – Brazil
{derosa,jlcarbonera,gmtorres,marabel}@inf.ufrgs.br
Abstract. In previous works, it was introduced an approach to support collabo-
rative construction and evolution of domain ontologies based on UFO-A. How-
ever, there are areas of knowledge, like in the petroleum geology, where we need
to represent some natural/geological phenomena which aren’t possible to be
well represented by UFO-A constructs, by the fact that this concepts are treated
as events that occur during time. Thus, this paper presents the results of the
study to support events from UFO-B in an ontology collaborative construction
environment, which initially was designed to maintain a collaboration record
from a domain ontology based on UFO-A.
1. Introduction
Recently, Torres’ work [Torres et al. 2011, Torres 2012] has introduced an approach to
building domain ontologies in a collaborative manner, in which the coherence in the ne-
gotiation of meaning during the collaboration is established with the use of a foundational
ontology called UFO [Guizzardi 2005]. However, Torres’ work just covers the fragment
from UFO called UFO-A, which is an on ontology of Endurants, leaving aside the rep-
resentation of events included in UFO-B (an ontology of Perdurants). UFO-A deals with
objects that are wholly present whenever they are present, we say that the Endurants are
in time, in the sense that, if in a circumstance c1 an endurant e has a property P1 and in a
circumstance c2 the property P2 (probably incompatible with P1 ), the object e is still the
same endurant. On the other hand, Perdurants are individuals composed of temporal parts
and, unlike Endurants, they happen in time, in the sense that they extend in time accu-
mulating temporal parts [Guizzardi et al. 2008a]. For the record, examples of Endurants
are a person, a car, a house, a rock; constitute example of Perdurants a conversation, a
football game, a business process, a depositional process etc.
The Carbonera’s work [Carbonera et al. 2011, Carbonera 2012] investigated the
role played by foundational ontologies in the problem solving methods involving visual
information, and proposed a cognitive model for visual interpretation of depositional pro-
cesses, within the Sedimentary Stratigraphy domain. This work also developed a domain
ontology in the area of Sedimentary Stratigraphy domain, in which were identified con-
cepts that should be represented as Perdurants, i.e., it is required a representation of the
temporal aspects in order to support reasoning.
So, there are knowledge domains in which their representation by a domain on-
tology requires the use of specific constructs that can represent temporal aspects, so this
knowledge can be represented in a reliable way.
278
This paper presents the results of the study to support events from UFO-B in an on-
tology collaborative construction environment, which initially was designed to maintain a
collaboration record from a domain ontology based on UFO-A. The choice of UFO-B, in-
stead of UFO-C, comes from the fact that UFO-C represents intentional agents (that have
intentions and goals), which is not our case. Our research group works with petroleum
geology, so we do not want to represent intentional agents, we want to model geological
and natural phenomena. This kind of phenomenon does not occur by the intention of an
agent, but for natural reasons that do not have a specific goal. It is important to be clear
that this work does not presents contributions in the creation of constructs for modeling
events or temporal aspects in a domain ontology, but it is about the requirement that our
modeling tool must have to support the collaborative construction of ontologies based on
both concepts from UFO-A and UFO-B.
This paper is organized as follows: in section 2 are presented the main concepts
envolving UFO. In section 3 we present the related works, which were the basis for the
development of this work. In section 4 are presented the changes made in the architecture
of the environment to support UFO-B events. In section 5, we conclude and anticipate
some future work.
2. Foundational Ontology: UFO
The UFO (Unified Foundational Ontology) [Guizzardi 2005, Guizzardi et al. 2008a] is
a Foundational Ontology which arose as a unification of concepts addressed by other
foundational ontologies. UFO is divides into 3 parts - UFO-A, UFO-B and UFO-C - that
structure notions of different scopes. The core of the UFO is the fragment called UFO-A,
which is an ontology of Endurants, and is concerned with structural aspects, like objects,
their types, their part/wholes, their intrinsic, relational properties and spaces of property
values, distinction between different types and their allowable relationships etc. UFO-B
is an ontology of Perdurants that deals with dynamic aspects, like events and their parts,
relations between events, object participation in events, temporal properties of entities,
time etc. UFO-C is built on top of UFO-A and UFO-B to systematize social aspects, like
agents, intentional states, goals, actions, norms, social commitments among many others.
A complete and detailed description about UFO’s fragments is outside the scope
of this paper. For a more detailed description of UFO-A and UFO-B, including their logi-
cal meaning, refer to [Guizzardi 2005, Guizzardi et al. 2008a, Guizzardi et al. 2008b], in
which the theoretical foundation of this work was based.
3. Collaborative Construction of Domain Ontologies
The work in [Torres et al. 2011] and [Torres 2012] presents an approach to build visual
domain ontologies in a collaborative way using meta-data based on foundational ontolo-
gies. It makes use of the concepts from the foundational ontology UFO, seeking a well-
structured construction of domain ontologies that could serve as a future reusable artifact.
Furthermore, a goal of using foundational ontologies is to establish a theoretical basis to
achieve consistency in the negotiations of meaning during the collaboration process. The
collaborative aspect is motivated by the fact that knowledge domains are not static, they
evolve as new elements become part of the domain or when elements become obsolete.
These changes must be adapted to the domain model, updating the ontology by adding
279
or removing elements. As knowledge about a certain domain can belong to several ge-
ographically dispersed collaborators, a collaborative process to create and maintain an
ontology helps to make explicit the changes that occur in this ontology, and also makes
explicit the concepts involving the vocabulary used by different collaborators.
In order to support the creation of domain ontologies in a collaborative way, two
meta-data ontologies are used: the R.O. (Representation Ontology) and C.O. (Collabo-
ration Ontology). The R.O. defines primitives to represent the domain ontology, while
the C.O. defines primitives to represent the collaboration events. The domain ontology
components are defined as instances of the concepts of the R.O., and the changes made
in the domain ontology are defined as instances of the concepts of C.O.. The meta-
ontology R.O. extends some of the major components of ontologies (concept, property,
relation, axiom) specializing them in the constructs proposed by foundational ontology
UFO-A [Guizzardi 2005], providing thus an ontological foundation for the model. The
meta-ontology C.O. defines which events of collaboration can be performed in the do-
main ontology. The instances of C.O. are the changes related to what is represented by
the R.O., which is the domain ontology. Figure 1 shows an example of the interaction
in the ontology of meta-data and collaboration history generated due to changes in the
domain ontology.
Figure 1. The collaboration structure
Currently, this approach covers Endurants objects in building models. But it is im-
portant, for Geology interpretation or natural phenomena, to represent the transformation
of objects (Endurants) through the events.
4. Supporting Events from UFO-B
This work is an extension of the work presented in [Torres et al. 2011, Torres 2012], in
which it was developed an environment to support collaborative construction and evolu-
tion of domain ontologies based on UFO-A. Now, we are concerned with the temporal
aspects, i.e., with the representation of UFO-B events in that same environment. This
section presents the modifications realized in the original meta-data ontologies (R.O. and
C.O.) used to specify the structure of the domain ontology components and collaboration
280
episodes. These modifications were realized in order to represent the temporal aspects
in the domain ontologies created for this system. The first change made was to organize
the meta-data ontologies to reflect the taxonomic structure of the foundational ontology
UFO. Figure 2 depicts the main differences between the original and the new taxonomy
in the R.O..
Figure 2. On the left, a fragment of the former R.O.. On the right, the updates
performed
We renamed some terms of this meta-data ontology to conform to terminology
used in UFO, and thus avoid possible confusion between the terms used in this work
and in the UFO. For example, the term OntologyComponent was the concept from which
all other concepts were specialized. In UFO, the concept that is the top concept, i.e.,
the concept from which all other concepts were specialized is the concept named Entity,
so we renamed the term OntologyComponent to Entity. We have also made changes in
the taxonomy of this meta-data ontology. For example, the Relations were structured
as expected in the UFO, i.e., as an EndurantUniversal. There were many changes in
nomenclature and taxonomy to match the terms used with those predicted in the UFO.
In order to organize the changes made, we will first present the theoretical con-
cepts of UFO-B, and then show the changes made to represent the concepts in the ap-
proach proposed by Torres. Below, we explain some theoretical concepts from UFO-B
along with the modifications made in the meta-data ontology to support the representation
of them.
Mereological Structure: Events are examples of entities that obey the so-called Exten-
sional Mereology, we have that: i) No event is part of itself; ii) If event X is part
of event Y then event Y is not part of event X; iii) If event X is part of event Y
and event Y is part of event Z then event X is part of event Z; iv) If event Y is
part of event X then there is an event Z disjoint from Y which is also part of X;
v) Two events are the same if and only if they are composed of exactly the same
parts. Figure 3.A depicts the mereology structure in the R.O..
Ontological Dependence: The Events from UFO-B are ontologically dependent on a
relationship of participation with any object from UFO, i.e., an event exists only
281
Figure 3. A) the mereologic structure of events and the Participation concept; B)
the role differentiation in the UFO-B; C) the temporal qualities; D) the time interval
relations
if at least one object is participating on it. The UFO-B provides the use of a
special construct to establish a participation relation with one object, the construct
is called Participation and it is depicted in Figure 3.A.
Role Diferentiation: When an object is participating in an event, he is playing a role in
this event, which is not the same role that this object could play out of this event.
Then we specialize the UFO-A Role concept in two types of roles: Those who are
existentially dependent on some Endurant and those who are existentially depen-
dent on some Perdurant. We call, respectively: Relational Role and Processual
Role. Figure 3.B depicts this distinction in the R.O..
Temporal Qualities: Events can be bearer of qualities, for example, a football game can
be disputed, a conversation can be boring, and depositional process can be slow.
Every event has a common property: its duration. Every event is framed by a
time interval. And a time interval is associated with a temporal structure, which
is analogous with a quality structure. An event is framed by a time interval T if
we have T Pb and T Pe , that are quality values in a given temporal structure and,
T Pb is the begin time point, and T Pe is the end time point. Figure 3.C depicts the
changes realizes in the R.O. in order to represent the time structures.
Time Interval Relations: Events may have relationship between then. We have a special
kind of relationship between events which can be used to establish relationships
of a partial or total ordering in their occurrences, for this we use de called Allen’s
Relations. These relations are added in the R.O. and it is depicted in the Figure
3.D.
Change in the State of Affairs: Events can change the world by changing the State of
Affairs. A Situation is defined in the UFO-A and it represents a particular state of
affairs, i.e., a situation can be seen as a portion of reality that can be understood
as a whole. An event takes one situation to another: from a pre-situation to a post-
situation, i.e., an event has a pre-situation relationship with a particular situation,
and a post-situation relationship with another particular situation different from
first. We can define a Situation as a set consisting of several objects (including an-
other situations). The inclusion of the Situation construct in the R.O. are depicted
in Figure 3.D.
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The modifications in the C.O. are still not completed in the date that this paper was
written. Then, this discussion will be taken at a future opportunity.
5. Conclusions and Future Work
This work presented some modifications performed in the Torres’ work to support the
representation of UFO-B events in an ontology collaborative construction system. The
objective of this project, in the long run, is to support the reasoning of geological inter-
pretation of depositional process based on described characteristics of sedimentary rocks.
We expect that a well founded domain ontology, built with the support of a collaborative
tool, would express the geological concepts in a more precise way, therefore supporting
useful interpretations.
The meta-ontologies introduced in the Torres’ work were developed to provide
a basis for the collaborative construction of language-independent domain ontologies,
and were based on the constructs from UFO-A. Now, this work is expanding this basis,
improving the meta-ontologies and supporting the representation of events and temporal
aspects inherited from UFO-B. Currently this work is in constant development.
6. Acknowledgements
The scholarships in this project are funding by the program PETROBRAS PFRH 17 and
CNPq. Material funding was supported by ENDEEPER Knowledge Systems.
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