Carlo Meghini

A model of information retrieval based on a terminological logic

According to the logical model of Information Retrieval (IR), the task of IR can be described as the extraction, from a given document base, of those documents d that, given a query q, make the formula d ! q valid, where d and q are formulae of the chosen logic and ! denotes the brand of logical implication formalized by the logic in question. In this paper, although essentially subscribing to this view, we propose that the logic to be chosen for this endeavour be a Terminological Logic (TL): accordingly, the IR task becomes that of singling out those documents d such that d q, where d and q are terms of the chosen TL and denotes subsumption between terms. We call this the terminological model of IR. TLs are particularly suitable for modelling IR; in fact, they can be employed: 1) in representing documents under a variety of aspects (e.g. structural, layout, semantic content); 2) in representing queries; 3) in representing lexical, thesaural knowledge. The fact that a single logical language can be used for all these representational endeavours ensures that all these sources of knowledge will participate in the retrieval process in a uniform and principled way. In this paper we introduce Mirtl, a TL for modelling IR according to the above guidelines; its syntax, formal semantics and inferential algorithm are described. This paper appears in the Proceedings of ACM SIGIR93, 16th International Conference on Research and Development in Information Retrieval, Pittsburgh, PA, 1993, pages 298{307.

Conceptual modeling of multimedia documents

An approach to the document-retrieval problem that aims to increase the efficiency and effectiveness of document-retrieval systems by exploiting the semantic contents of the documents is presented. The document retrieval problem is delineated, and conceptual document modeling basics and requirements are discussed. An experimental system, the Multimedia Office Server (Multos), which implements some of the document-model concepts described, is presented.<<ETX>>

Deep learning for decentralized parking lot occupancy detection

We propose an effective CNN architecture for visual parking occupancy detection.The CNN architecture is small enough to run on smart cameras.The proposed solution performs and generalizes better than other SotA approaches.We provide a new training/validation dataset for parking occupancy detection. A smart camera is a vision system capable of extracting application-specific information from the captured images. The paper proposes a decentralized and efficient solution for visual parking lot occupancy detection based on a deep Convolutional Neural Network (CNN) specifically designed for smart cameras. This solution is compared with state-of-the-art approaches using two visual datasets: PKLot, already existing in literature, and CNRPark-EXT. The former is an existing dataset, that allowed us to exhaustively compare with previous works. The latter dataset has been created in the context of this research, accumulating data across various seasons of the year, to test our approach in particularly challenging situations, exhibiting occlusions, and diverse and difficult viewpoints. This dataset is public available to the scientific community and is another contribution of our research. Our experiments show that our solution outperforms and generalizes the best performing approaches on both datasets. The performance of our proposed CNN architecture on the parking lot occupancy detection task, is comparable to the well-known AlexNet, which is three orders of magnitude larger.

The complexity of operations on a fragmented relation

Data fragmentation is an important aspect of distributed database design, in which portions of relations, tailored to the specific needs of local applications, are defined to be further allocated to the sites of the computer network supporting the database system. In this paper we present a theory of fragmentation with overlapping fragments to study the complexity of the problems involved in checking the completeness of a fragmentation schema and in querying and updating a fragmented relation. We analyze these problems from the complexity viewpoint and present sound and complete algorithms for their solution.

Europeana v1.0

The Europeana v1.0 is a Thematic Network project funded under the Commission’s eContentplus programme 2008 and is the successor network to the EDLnet thematic network that created the EDL Foundation and the Europeana prototype. The goal of the project is to develop an operational service and solve key operational issues related to the implementation and functioning of the European Digital Library. The work will include also a business development operation to ensure that a steady stream of content is made available in the Digital Library.

A unified interaction scheme for information sources

Commonly, for retrieving the desired information from an information source (knowledge base or information base), the user has to use the query language that is provided by the system. This is a big barrier for many ordinary users and the resulting interaction style is rather inflexible. In this paper we give the theoretical foundations of an interaction scheme that allows users to retrieve the objects of interest without having to be familiar with the conceptual schema of the source or with the supported query language. Specifically, we describe an interaction manager that provides a quite flexible interaction scheme by unifying several well-known interaction schemes. Furthermore, we show how this scheme can be applied to taxonomy-based sources by providing all needed algorithms and reporting their computational complexity.

Design, implementation and evaluation of a user generated content service for Europeana

The paper presents an overview of the user generated content service that the ASSETS Best Practice Network is designing, implementing and evaluating with the user for Europeana, the European digital library. The service will allow Europeana users to contribute to the contents of the digital library in several different ways, such as uploading simple media objects along with their descriptions, annotating existing objects, or enriching existing descriptions. The user and the system requirements are outlined first, and used to derive the basic principles underlying the service. A conceptual model of the entities required for the realization of the service and a general sketch of the system architecture are also given, and used to illustrate the basic workflow of some important operations. The planning of the user evaluation is finally presented, aimed at validating the service before making it available to the final users.

Querying fragmented relations in a distributed database

SummaryThe paper discusses the query optimization problem in a distributed database system supporting a complex fragmentation schema, in which different fragments can share the same set of data. The fragmentation and the distribution of data are assumed to be transparent to the user, who queries the database in terms of the global relations. The optimization of queries stated on a single fragmented relation is considered, and a method for its solution is presented. The method is based on an algorithm which calculates a set of virtual fragments that can alternatively be used to answer the query.

Describing Research Data: A Case Study for Archaeology

The growth of the digital resources produced by the research activities demand the development of e-Infrastructures in which researchers can access remote facilities, select and re-use huge volumes of data and services, run complex experimental processes and share results. Data registries aim to describe uniformly the data of e-Infrastructures contributing to the re-usability and interoperability of big scientific data. However the current situation requires the development of powerful resource integration mechanisms that step beyond the principles guaranteed by the data registries standards. This paper proposes a conceptual model for describing data resources and services and extends the existing specifications for the development of data registries. The model has been implemented in the context of the ARIADNE project, a EU funded project that focuses on the integration of Archaeological digital resources all over the Europe.

EuropeanaLabs: An Infrastructure to Support the Development of Europeana

This document describes the Europeana Development and communication infrastructure, called EuropeanaLabs, built inside the EU projects Europeana and Europeana v. 2. The EuropeanaLabs consists of a number of servers, storages and communication devices; it is used to create Virtual Machines, called sandboxes, used by Europeana foundation communities. EuropeanaLabs provides a test environment, for applications and demos, to several cultural heritage and technology projects, most of them funded by EU, in addition it features a set of servers for cooperative work. In this paper we present the general architecture of the EuropeanaLabs infrastructure.