Antonella Poggi | Università degli Studi "La Sapienza" di Roma (original) (raw)

Papers by Antonella Poggi

MAGISTER: Multidimensional Archival Geographical Intelligent System for Territorial Enhancement a... more MAGISTER: Multidimensional Archival Geographical Intelligent System for Territorial Enhancement and Representation The paper describes interdisciplinary approach, goals and output of MAGISTER project, whose main aim is the creation of an Ontology-Based Data Access (OBDA) in order to manage and put in relation different kind of data and sources starting from both spatial and geographical information. MAGISTER: Systeme multidimensionnel de geographie intelligente pour l’amelioration et la representation territoriale Cet article decrit l’approche interdisciplinaire, les objectifs et premier resultats du projet MAGISTER, dont l’objectif principal est la creation d’un Ontology-Based Data Access (OBDA) afin de gerer et mettre en relation differents types de donnees et de sources a partir d’informations spatiales et geographiques.

Conference on Bases de Donnees …, 2002

Bases de données semi-structurées Mots-clefs: Entrepôt de données, XML, Bases de données semi-str... more Bases de données semi-structurées Mots-clefs: Entrepôt de données, XML, Bases de données semi-structurées Données temporelles Services Web Résumé: Dans cet article, nous nous intéressonsà la construction d'entrepôts dynamiquesà partir de ressources du Web, en utilisant notamment des services disponibles sur le web. Notre contribution tient essentiellementà la définition d'une nouvelle architecture basée autour de services web (e.g. SOAP) et du language ActiveXML, nous permettant de résoudre notamment les problèmes suivant: (i) l'acquisition de pages du Web, (ii) le contrôle des changements de ces pages et (iii) l'enrichissement des données et méta-données par l'utilisation de services Web. Le système est développé en Ac-tiveXML, un langage et un système permettant l'intégration d'appelsà des services Web au sein d'un document XML.

The goal of DELOS Task 4.8 Task-centered Information Management is to provide the user with a Tas... more The goal of DELOS Task 4.8 Task-centered Information Management is to provide the user with a Task-centered Information Management system (TIM), which automates user’s most frequent activities, by exploiting the collection of personal documents considered as a Digital Library. In previous work we have explored the issue of managing personal data by enriching them with semantics according to a Personal Ontology, i.e. a user-tailored description of her domain of interest. Moreover, we have proposed a task specification language and a top-down approach to task inference, where the user specifies main aspects of the tasks using forms of declarative scripting. Recently, we have addresses new challenging issues related to TIM personalization and user’s task inference. More precisely, the first main contribution of this paper is the design of a profiling ontology for the user, that can be used to semi-automatically populate the Personal Ontology. The second contribution is the investigatio...

Most existing human-computer interfaces are now based on the WIMP (Windows, Icons, Menus, Pointer... more Most existing human-computer interfaces are now based on the WIMP (Windows, Icons, Menus, Pointers) paradigm and on the desktop metaphor. Each application is targeted towards editing one specific type of “document”. Current

Information Systems: People, Organizations, Institutions, and Technologies, 2009

This demonstration concerns the visual user interface of the On-TIME system, a task-centered info... more This demonstration concerns the visual user interface of the On-TIME system, a task-centered information management system, whose aim is to actively participate to and support the user tasks. The design of a user friendly interface is one of the key challenges that needs to be addressed for the success of On-TIME. Being On-TIME based on the use of a so-called Personal Ontology to provide a semantic account to user's personal data, the interface has to allow the user to easily browse the ontology. On the other hand, it has to address the management of tasks. This requires to both suggest tasks that the user might be willing to perform, and to support her while executing tasks. We present a typical user scenario in order to illustrate a possible interaction with the On-TIME interface, and discuss some preliminary user evaluation.

16th IEEE International Workshops on Enabling Technologies: Infrastructure for Collaborative Enterprises (WETICE 2007), 2007

In this paper, we present the architecture of the research project WORKPAD 1. This project aims a... more In this paper, we present the architecture of the research project WORKPAD 1. This project aims at designing and developing an innovative service-oriented software infrastructure for supporting collaborative work of human operators in emergency/disaster scenarios. In such scenarios, different teams, belonging to different organizations, need to collaborate with one other; each team member is equipped with handheld devices (PDAs) and communication technologies, and should carry on specific tasks. In such a case we can consider the whole team as carrying on a process, and the different teams collaborate through the "interleaving" of all the different processes. Each team is supported by some back-end centres, which need to cooperate at an inter-organizational level. Modelling interface Data access interface (Web service-based) Local data source mappings P2P mappings Knowledge core Local data source Local connection management communication Other back-end peer Other back-end peer Front-end Connection management communication (Web Service-based) Modelling interface Data access interface (Web service-based) Local data source mappings P2P mappings Knowledge core Local data source Local connection management communication Other back-end peer Other back-end peer Front-end Connection management communication

We propose a new methodology, a language and tools for the design and construction of Web data wa... more We propose a new methodology, a language and tools for the design and construction of Web data ware- houses. Our approach is Service Oriented, in that our framework makes an extensive use of Web Ser- vices and semi-structured data (XML) to define the data structures, the services and the connections be- tween them. We present an experimental version of the system that has been built using this framework. It uses external Web Services such as Google's We- bAPI, and Web Services we implemented, including a scalable crawler, a classification and clustering en- gine based on links semantic, a Pagerank module and a versioning system. An important aspect in our work is that our architecture allows the warehouse data to change in a continuous way, when Web data changes, or when the users refine their choices. GUI: We will present a graphical user interface to design and construct a dynamic warehouse. The GUI gives a graphical representation of both our data model and ser- vice model, ...

World Wide Web, 2009

In the present global society, information has to be exchangeable in open and dynamic environment... more In the present global society, information has to be exchangeable in open and dynamic environments, where interacting users do not necessarily share a common understanding of the world at hand. This is particularly true in P2P scenarios, where millions of autonomous users (peers) need to cooperate by sharing their resources (such as data and services). We propose the Esteem approach (Emergent Semantics and cooperaTion in multi-knowledgE EnvironMents), where a comprehensive framework and a platform for data and service discovery in P2P systems are proposed, with advanced solutions for trust and quality-based data management, P2P infrastructure definition, query processing and dynamic service discovery in a context-aware scenario. In Esteem, semantic communities are built This paper has been partially funded by the ESTEEM PRIN project of the Italian Ministry of Education, University and Research.

Journal of Web Semantics, 2010

This paper takes as its premise that the web is a place of action, not just information, and that... more This paper takes as its premise that the web is a place of action, not just information, and that the purpose of global data is to serve human needs. The paper presents several component technologies, which together work towards a vision where many small micro-applications can be threaded together using automated assistance to enable a unified and rich interaction. These technologies include data detector technology to enable any text to become a start point of semantic interaction; annotations for web-based services so that they can link data to potential actions; spreading activation over personal ontologies, to allow modelling of context; algorithms for automatically inferring 'typing' of web-form input data based on previous user inputs; and early work on inferring task structures from action traces. Some of these have already been integrated within an experimental web-based (extended) bookmarking tool, Snip!t, and a prototype desktop application On Time, and the paper discusses how the components could be more fully, yet more openly, linked in terms of both architecture and interaction. As well as contributing to the goal of an action and activity-focused web, the work also exposes a number of broader issues, theoretical, practical, social and economic, for the Semantic Web.

Journal of Applied Logic, 2010

The relational model has recently been extended to so-called K-relations in which tuples are assi... more The relational model has recently been extended to so-called K-relations in which tuples are assigned a unique value in a semiring K. A query language, denoted by RA C K , similar to the classical positive relational algebra, allows for the querying of K-relations. In this paper, we define more expressive query languages for K-relations, that extend RA C K to express operations on annotated tuples that are natural extensions of corresponding operations of the relational algebra, namely difference and constant annotations. We investigate conditions on semirings under which these operations can be added in a natural way, and establish basic properties of these query languages. Moreover, we show how the provenance semiring of Green et al. can be extended to record provenance of data in the presence of difference and constant annotations. Finally, we investigate completeness of RA C K and extensions thereof in the sense of Bancilhon and Paredaens (BP). K are already established in [11], less is known about its expressive power. Furthermore, it was left open in [11] how to incorporate difference in RA C K to get a full relational algebra on K-relations. Hence, our goal is twofold. On one hand, we define more expressive query languages for K-relations, that extend RA C K to express operations on annotated tuples that are natural extensions of corresponding operations of the relational algebra. On the other hand, we investigate completeness of RA C K and extensions thereof. Recall

Dix, Alan and Catarci, T. and Katifori, A. and Lepouras, G. and Poggi, A. (2007) Task-Centered In... more Dix, Alan and Catarci, T. and Katifori, A. and Lepouras, G. and Poggi, A. (2007) Task-Centered Information Management. In: First International DELOS Conference. LNCS (4877). Springer, pp. 197-206. ... Full text not available from this repository. ... Computing Repository is ...

Proc. of the 4th International Conference on Information Systems for Crisis Response and Management (ISCRAM), Delft, The Netherlands, May 13, 2007

The most effective way to design an emergency management system matching user needs is to perform... more The most effective way to design an emergency management system matching user needs is to perform a User-Centered Design; it relies on continuous interactions with end-users in order to understand better and better how organizations are arranged during emergencies, which data are exchanged and which steps are performed by organizations to face disastrous events. In this paper we (i) illustrate the methodology used to collect the user requirements for the emergency management system developed in the European ...

Proceedings of the AAAI Conference on Artificial Intelligence

In Ontology-Based Data Management (OBDM), an abstraction of a source query q is a query over the ... more In Ontology-Based Data Management (OBDM), an abstraction of a source query q is a query over the ontology capturing the semantics of q in terms of the concepts and the relations available in the ontology. Since a perfect characterization of a source query may not exist, the notions of best sound and complete approximations of an abstraction have been introduced and studied in the typical OBDM context, i.e., in the case where the ontology is expressed in DL-Lite, and source queries are expressed as unions of conjunctive queries (UCQs). Interestingly, if we restrict our attention to abstractions expressed as UCQs, even best approximations of abstractions are not guaranteed to exist. Thus, a natural question to ask is whether such limitations affect even larger classes of queries. In this paper, we answer this fundamental question for an essential class of queries, namely the class of monotone queries. We define a monotone query language based on disjunctive Datalog enriched with an ep...

We study the problem of designing reverse engineering techniques for associating semantic descrip... more We study the problem of designing reverse engineering techniques for associating semantic descriptions to existing data services. We base our proposal on the Ontology-Based Data Access paradigm, where a domain ontology is used to provide a semantic layer mapped to the data sources of an organization. The basic idea is to perform the reverse engineering of a data service, expressed a query over the data sources, by deriving a query over the ontology that explains the semantics of the data service in terms of the element of the ontology. We illustrate a formal framework for this problem, based on the notion of source-toontology rewriting, which comes in three variants, called sound, complete and perfect, respectively. We present a thorough complexity analysis of two computational problems, namely verification (checking whether a query is a sourceto-ontology rewriting of a given data service), and computation (computing a source-to-ontology rewriting of a data service).

We study the problem of associating formal semantic descriptions to data services. We base our pr... more We study the problem of associating formal semantic descriptions to data services. We base our proposal on the Ontology-Based Data Access paradigm, where a domain ontology is used to provide a semantic layer mapped to the data sources of an organization. The basic idea is to explain the semantics of a data service in terms of a query over the ontology. We illustrate a formal framework for this problem, based on the notion of source-to-ontology rewriting, which comes in three variants, called sound, complete and perfect, respectively. We present a thorough complexity analysis of two computational problems, namely verification (checking whether a query is a rewriting of a given data service), and computation (computing a rewriting of a data service). The architecture of many modern Information Systems is based on data services [11], i.e., services deployed on top of data stores, other services, and/or applications to encapsulate a wide range of data-centric operations. In order to rea...

OWL 2 QL is the profile of OWL 2 targeted to Ontology-Based Data Access (OBDA) scenarios, where l... more OWL 2 QL is the profile of OWL 2 targeted to Ontology-Based Data Access (OBDA) scenarios, where large amount of data are to be accessed and thus query answering is required to be especially efficient in the size of such data, namely AC0 in data complexity. On the other hand, the syntax and the semantics of the SPARQL query language for OWL 2 is defined by means of the Direct Semantics Entailment Regime (DSER), which considers queries including any assertion expressible in the language of the queried ontology, i.e., both ABox atoms, TBox atoms and inequalities expressed by means of DifferentIndividuals atoms. Thus, in this paper, we investigate query answering over OWL 2 QL under DSER. In particular, we show that, by virtue of the restricted meaning assigned to existential variables and union, query answering can be reduced to the evaluation of a Datalog program. Finally, we investigate query answering under a new SPARQL entailment regime, called Direct Semantics Answering Regime (DS...

Proceedings of the 7th International Conference on Web Intelligence, Mining and Semantics, 2017

OWL 2 QL is the pro le of OWL 2 targeted to Ontology-Based Data Access (OBDA) scenarios, where la... more OWL 2 QL is the pro le of OWL 2 targeted to Ontology-Based Data Access (OBDA) scenarios, where large amount of data are to be accessed, and thus answering conjunctive queries over data is the main task. However, this task is quite restrained wrt the classical KR Ask-and-Tell framework based on querying the whole theory, not only facts (data). If we use SPARQL as query language, we get much closer to this ideal. Indeed, SPARQL queries over OWL 2 QL, under the so-called Direct Semantics Entailment Regime, may comprise any assertion expressible in the language, i.e., both ABox atoms and TBox atoms, including inequalities expressed by means of DifferentIndividuals. Nevertheless this regime is hampered by the assumption that variables in queries need to be typed, meaning that the same variable cannot occur in positions of di erent types, e.g., both in class and individual position (punning). In this paper we dismiss this limiting assumption by resorting to a recent meta modeling semantics and show that query answering in the resulting entailment regime is polynomially compilable into Datalog (and hence PTIME wrt both TBox and ABox).

Artif. Intell., 2021

OWL 2 QL is a standard profile of the OWL 2 ontology language, specifically tailored to Ontology-... more OWL 2 QL is a standard profile of the OWL 2 ontology language, specifically tailored to Ontology-Based Data Management. Inspired by recent work on higher-order Description Logics, in this paper we present a new semantics for OWL 2 QL ontologies, called Metamodeling Semantics (MS), and show that, in contrast to the official Direct Semantics (DS) for OWL 2 , it allows exploiting the metamodeling capabilities natively offered by the OWL 2 punning. We then extend unions of conjunctive queries with both metavariables, and the possibility of using TBox atoms, with the purpose of expressing meaningful metalevel queries. We first show that under MS both satisfiability checking and answering queries including only ABox atoms, have the same complexity as under DS. Second, we investigate the problem of answering general metaqueries, and single out a new source of complexity coming from the combined presence of a specific type of incompleteness in the ontology, and of TBox axioms among the quer...