Aperitivo Informatico at FUB: new ways of inclusion and participation

One of the 28 events during the 5-day long “UniDays” (it, de) at the Free University of Bozen-Bolzano (FUB) was the “Aperitivo Informatico” (held this morning from 11 to about 2pm) that had as theme informatics & democracy with new forms of inclusion and direct participation, closing the digital divide, and online social networks.

The invited guests were: Gabriella Dodero, rector’s delegate for the “diversamente abili” (disabled), Rosella Gennari, FUB PI of the EU FP7 project TERENCE (Technology Enhanced Learning area) and national project LODE (a LOgic-based e-learning tool for DEaf children), Luca Nicotra, Secretary of Agorà Digitale, Paolo Campostrini, a journalist of the Alto Adige newspaper, and Paolo Mazzucato, a journalist for Radio Rai. My role as invited guest was to represent Informatici Senza Frontiere (ISF, Informaticians without borders, an Italian NGO).

The first topics that passed the revue were about what FUB does for the differently abled, noting that there is (and has been) support for blind and deaf people both in the FUB structures and providing suitable software etc, and Gabriella Dodero is also looking into support for people with dyslexia (even though in Italy it is not categorized as a disability). Rosella Gennari zoomed in on deaf children and development of suitable computer-supported learning environments for young poor comprehenders. Luca Nicotra introduced Agorà Digitale, a political/lobby organization concerned with democracy, privacy, net neutrality, and the way of dissemination of information that is an essential component of a well-functioning democracy.

I introduced various projects of ISF, which does not look so much at so-called trash-ware (shipping [dumping?] old hardware to less computerized locations), but, among others, putting effort into developing suitable software for the locale, such as the (open source) openHospital implemented in countries such as Kenya, Uganda, and Benin for day-to-day management of hospital data, installing financial software for managing microcredit in Madagascar, reconnecting Congo to the internet (hospitals and the University Masi Manimba in particular), openStaff in Chad to, among others, provide assistance to refugees, developing controlInfantil in Ecuador, as well as projects in Italy to narrow the digital divide, such as connecting hospitalized children with a long-term illness to their family, friends, and school in a hospital in Brescia, and a computer room and providing basic IT courses in the casa dell’ospitalità in Mestre. (note: some information about these and other projects is also available in English)

Other topics that passed the revue what the future might bring us for Internet & democratization and if the Internet merits to be awarded the Nobel Peace prize (see also Internet for peace). Response on the second topic was diverse, with Dodero continuing her work regardless if it were awarded a prize or not, Gennari jokingly mentioning that after Obama, then, well, why not, whereas Nicotra was not at all that positive about the idea because the Internet can be used for the worse as well and become monopolized like TV and radio before it. Like with most, if not all, technologies, they can be used for the benefit and detriment of society and humankind, and this holds for the Internet just as much and in all three principal components: regarding the hardware (and limitations to connect due to, e.g., blockades), the software for accessibility by diverse groups of peoples, and the generation & dissemination of (dis)information. That is, Internet technologies themselves are not intrinsically good and just (the first networked computers were at DARPA, a research facility of USA defense forces). And perhaps it is not too far fetched to stretch the information component to the ‘Web of Knowledge’ with its current incarnation as the Semantic Web—thus far, it has been used mostly to indeed share, link, and integrate data, information, and knowledge more efficiently and effectively; let us keep focussing on the positive, constructive, side of the usage of Semantic Web technologies.


Constraints for migrating relations over time

Migrating objects in a database is nothing new—employees become managers, MSc students PhD students and so forth—and this has been investigated and implemented widely in temporal databases. But imagine a scenario for an airline company’s passenger RDBMS and a passenger who books a flight, hence we have a relation ⟨John, AZ123⟩ ∈ Booking with John ∈ Passenger and AZ123 ∈ Flight, which is normally followed by the events that John also checks in and boards the plane afterward, i.e., ⟨John, AZ123⟩ ∈ CheckIn and then ⟨John, AZ123⟩ ∈ Boarding. While the booking relation holds even after the tuple extended to the check-in relation, i.e., ⟨John, AZ123⟩ is a member of both Booking and CheckIn relations, this is not the case for the step from check-in to boarding which causes the tuple ⟨John, AZ123⟩ to be moved from one table to another in the operational database. In addition, for any tuple that is member of the Boarding relation, we know that it must have been a member of CheckIn relation sometime earlier. Clearly, airline companies implement some code to keep track of such changes, but how to represent this in a conceptual data model?

Or take a simple change in relation between two objects can be caused by the fact that a is structurally a part of b but a gets loose so after that a becomes spatially contained in b; e.g., a component in a medical device breaks loose due to wear and tear. Then it would be nice if a fault detection system can send such a message back to control, compared to the imprecise “there’s something wrong over there”.

A related issue is keeping track of the status of the same relation. Take, for instance, the issues with subquantities with, say, a bottle of wine and pouring a subquantity of the wine into a wineglass so that this subquantity in the glass used to be—but not is—a subquantity of the wine in the bottle and one wants to maintain traceability of quantities over time. This is important especially in the food industry for food safety in the food processing chain, hence, the data management has to be able to deal with such cases adequately and transparently.

Perhaps surprisingly, there is no conceptual data modelling language that lets you model the business knowledge where relations migrate during the conceptual analysis stage.  By relation migration, I mean the change of membership of a tuple from one relation to another. Thus, relation migration is distinct from state transition diagrams that concern states of single objects, from activity diagrams that concern processes but do not explicitly consider the participating entities, and from interaction diagrams for modelling use cases. Here we focus explicitly on the migration of facts/tuples/relation instances and the corresponding temporal behaviour of fact types/relations. So, in analogy to object migration, there is a usefulness of a similar set of constraints for relations that can be called relation migration.

Alessandro Artale and I specified the basic constraints that hold for relation migration, which recently got accepted for the ORM’10 workshop co-located with the OTM conference. The paper’s [1] abstract is as follows:

Representing and reasoning over evolving objects has been investigated widely. Less attention has been devoted to the similar notion of relation migration, i.e., how tuples of a relation (ORM facts) can evolve along time. We identify different ways how a relation can change over time and give a logic-based semantics to the notion of relation migration to capture its behaviour. We also introduce the notion of lifespan of a relation and clarify the interactions between object migration and relation migration. Its use in graphical conceptual data modelling is illustrated with a minor extension to ORM2 so as to more easily communicate such constraints with domain experts.

We distinguish between evolution constraints—specifying how elements of a relation can possibly migrate to another relation—persistence constraints—specifying persistent states for a relation—and quantitative evolution constraints—specifying the exact amount of time for the relation migration to happen. In addition, one has to consider the lifespan of relations. Together, they result in 15 axioms for the evolution and persistence constraints, and 3 propositions concerning the logical implications with respect to subsumption and relation migration, relation migration vs. lifespan, and objects vs. a relation’s lifespan.

Concerning the interaction object and relation migration, we found two types, one where an object migration forces a relation to migrate, and one where a relation migration forces an object migration. For instance, take a company where, at some point in time, each employee will be promoted within the same department he or she works for (for simplicity: the employee works for exactly one department) and such that demotion does not occur. This means an object migration of type PEX (Persistent Extension) between Employee and Manager (see figure, below). This forces a relation migration of type RPEX between worksFor and manages in order to maintain consistency of the conceptual data model (see figure below).

Example of an object migration (dashed purple arrow) that forces a relation migration (dashed green arrow)

The last word has not been said yet about incorporating rigidity fully in this framework, nor tractable reasoning with relation migration, but at least the foundational aspects of relation migration have been identified and characterized formally, which already can be added to conceptual data modelling languages, as illustrated for the Object-Role Modeling language in [1].


[1] Keet, C.M. and Artale, A. A basic characterization of relation migration. International Workshop on Fact-Oriented Modeling (ORM’10), Crete, Greece, October 27-29, 2010. Meersman, R., Herrero, P. (Eds.), OTM Workshops, Springer, Lecture Notes in Computer Science LNCS. (to appear)