Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2011
The paper presents an overview of the user generated content service that the ASSETS Best Practic... more 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 ...
We consider a general form of information sources, consisting of a set of objects classified by t... more We consider a general form of information sources, consisting of a set of objects classified by terms arranged in a taxonomy. The query-based access to the information stored in sources of this kind, is plagued with uncertainty, due, among other things, to the possible linguistic mismatch between the user and the object classification. To overcome this uncertainty in all situations in which the user is not finding the desired information and is not willing or able to state a new query, the study proposes to extend the classification, in a way that is as reasonable as possible with respect to the original one. By equating reasonableness with logical implication, the sought extension turns out to be an explanation of the classification, captured by abduction. The problem of query evaluation on information sources extended in this way is studied and a polynomial time algorithm is provided for the general case, in which no hypothesis is made on the structure of the taxonomy. The algorithm is successively specialized on a most common kind of information sources, namely sources whose taxonomy can be represented as a directed acyclic graph. It is shown that query evaluation on extended sources is easier for this kind of sources. Finally, two applications of the method are presented, which capture very important aspects of information access: information browsing and query result ranking.
We consider a general form of information sources, consisting of a set of objects classified by t... more We consider a general form of information sources, consisting of a set of objects classified by terms arranged in a taxonomy. The query-based access to the information stored in sources of this kind, is plagued with uncertainty, due, among other things, to the possible linguistic mismatch between the user and the object classification. To overcome this uncertainty in all situations in which the user is not finding the desired information and is not willing or able to state a new query, the study proposes to extend the classification, in a way that is as reasonable as possible with respect to the original one. By equating reasonableness with logical implication, the sought extension turns out to be an explanation of the classification, captured by abduction. The problem of query evaluation on information sources extended in this way is studied and a polynomial time algorithm is provided for the general case, in which no hypothesis is made on the structure of the taxonomy. The algorithm is successively specialized on a most common kind of information sources, namely sources whose taxonomy can be represented as a directed acyclic graph. It is shown that query evaluation on extended sources is easier for this kind of sources. Finally, two applications of the method are presented, which capture very important aspects of information access: information browsing and query result ranking.
In this study we address the problem of answering queries over a peer-to-peer system of taxonomyb... more In this study we address the problem of answering queries over a peer-to-peer system of taxonomybased sources. A taxonomy states subsumption relationships between negation-free DNF formulas on terms and negation-free conjunctions of terms. To the end of laying the foundations of our study, we first consider the centralized case, deriving the complexity of the decision problem and of query evaluation. We conclude by presenting an algorithm that is efficient in data complexity and is based on hypergraphs. More expressive forms of taxonomies are also investigated which however lead to intractability. We then move to the distributed case, and introduce a logical model of a network of taxonomy-based sources. On such network, a distributed version of the centralized algorithm is then presented, based on a message passing paradigm, and its correctness is proved. We finally discuss optimization issues, and relate our work to the literature.
Searching the Web can be frustrating if the sought information is not related to a well defined a... more Searching the Web can be frustrating if the sought information is not related to a well defined and popular topic of interest or supplied by renowned Web Sites. One of the main goal of the activities in the area of the Semantic Web is to overcome this problem. The Digital Library (DL) arena is a suitable place to take up the challenge. The growing interest in the Digital Libraries along with the publishing of generalized software that simplifies the building of such systems, has recently improved the standardization of concept and functionalities of DLs, DL Systems and DL Management Systems (DLMS). A significant contribution in this area has been given by EU-funded projects in this area, namely DELOS, BRICKS and DILIGENT. This paper describes the Query Manager of the BRICKS-DLMS, which implements a distributed information retrieval capability, offered in the form of simple search (Google-like) or of advanced search, the latter based on knowledge represented by metadata coming from different schemas. Cross-language discovery, and personalized query and query results, based on user profiles, are other significant characteristics of BRICKS-DLMS Query Manager.
The paper presents an overview of the user generated content service that the ASSETS Best Practic... more The paper presents an overview of the user generated content service that the ASSETS Best Practice Network has designed, implemented and evaluated 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 aim of the BRICKS project is to design, develop and maintain an open user and service-oriente... more The aim of the BRICKS project is to design, develop and maintain an open user and service-oriented infrastructure to share knowledge and resources in the Cultural Heritage domain. Typical usage scenarios are integrated queries among several knowledge resource, e.g. to discover all Italian artifacts from renaissance in the European museums or to follow the life cycle of historic documents. These examples are specific applications, which are running on top of the BRICKS infrastructure. The BRICKS infrastructure will use the Internet as a backbone and will fulfil the requirements of expandability, graduality of engagement, scalability, availability, and interoperability.
Digital Library (DL) interoperability, as it is being reported in the DL.org Digital Library Refe... more Digital Library (DL) interoperability, as it is being reported in the DL.org Digital Library Reference Model, is intimately related to function interoperability. A prerequisite for the later is an appropriate function description, publication and discovery mechanisms. The importance of a framework which accommodates the specification of key DL function characteristics such as interface, behavior, dependencies and semantics, has been highlighted by the DL.org Functionality working group. Such a framework should be used in appropriate registries, which cater for the publication and discovery of DL functionality. In this paper we report the findings of the DL.org Functionality working group in terms of a DL function description framework and a set of contemporary registries that can serve as the basis for the provision of a DL Function interoperability enabling registry.
... in 1973 Founding and Former Series Editors: Gerhard Goos, Juris Hartmanis, and Jan van Leeuwe... more ... in 1973 Founding and Former Series Editors: Gerhard Goos, Juris Hartmanis, and Jan van Leeuwen Editorial Board David Hutchison Lancaster ... 348 Ilyes Jenhani, Nahla Ben Amor, Salem Benferhat, and Zied Elouedi Towards a Logic for Abstract MetaFinite State Machines ...
Proceedings of the 1st International Workshop on Collaborative Annotations in Shared Environment metadata, vocabularies and techniques in the Digital Humanities - DH-CASE '13, 2013
We present a model for complex documents possibly consisting of a hierarchically structured set o... more We present a model for complex documents possibly consisting of a hierarchically structured set of images or texts. Documents are represented both at the form level (as sets of physical features of the representing objects), at the content level (as sets of properties of the represented entities), and at the structure level. A uniform and powerful query language allows queries to be issued that transparently combine features pertaining to form, content and structure alike. Queries are expressions of a (fuzzy) logical language. While that part of the query that pertains to (medium-independent) content is "directly" processed by an inferential engine, that part that pertains to (medium-dependent) form is entrusted to specialised document processing procedures linked to the logical language by a procedural attachment mechanism. The model thus combines the power of state-of-the-art document processing techniques with the advantages of a clean, logically defined framework for understanding multimedia document retrieval.
Proceedings of the 16th annual international ACM SIGIR conference on Research and development in information retrieval - SIGIR '93, 1993
According to the logical model of Information Retrieval (IR), the task of IR can be described as ... more 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
Proceedings of the 18th annual international ACM SIGIR conference on Research and development in information retrieval - SIGIR '95, 1995
Images are a communication medium, hence objects of a linguistic nature having a form and a conte... more Images are a communication medium, hence objects of a linguistic nature having a form and a content. The form of an image is the image appearance and is understood as depicting a scene, the image content. The relationship between the form of an image and its content is established through a process of interpretation, capturing the meaning of the image form. Any information need on images can, and indeed has to, be seen as addressing either the image form, or its content, or the relationship between them. Consequently, any general, domain independent image retrieval facility should be based on a model supporting all these aspects of images. An image retrieval model, based on classical logic, is proposed which fulfills this basic requirement.
A taxonomy-based source consists of a taxonomy and a database storing objects that are indexed in... more A taxonomy-based source consists of a taxonomy and a database storing objects that are indexed in terms of the taxonomy. For this kind of sources, we describe a flexible interaction scheme that allows users to retrieve the objects of interest without having to be familiar with the terms of the taxonomy or with the supported query language. Specifically we describe an interaction manager whose functionality unifies several well-known interaction schemes including query by example, answer enlargement/reduction, query relaxation/restriction, index relaxation/contraction, feedback and adaptation mechanisms.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2011
The paper presents an overview of the user generated content service that the ASSETS Best Practic... more 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 ...
We consider a general form of information sources, consisting of a set of objects classified by t... more We consider a general form of information sources, consisting of a set of objects classified by terms arranged in a taxonomy. The query-based access to the information stored in sources of this kind, is plagued with uncertainty, due, among other things, to the possible linguistic mismatch between the user and the object classification. To overcome this uncertainty in all situations in which the user is not finding the desired information and is not willing or able to state a new query, the study proposes to extend the classification, in a way that is as reasonable as possible with respect to the original one. By equating reasonableness with logical implication, the sought extension turns out to be an explanation of the classification, captured by abduction. The problem of query evaluation on information sources extended in this way is studied and a polynomial time algorithm is provided for the general case, in which no hypothesis is made on the structure of the taxonomy. The algorithm is successively specialized on a most common kind of information sources, namely sources whose taxonomy can be represented as a directed acyclic graph. It is shown that query evaluation on extended sources is easier for this kind of sources. Finally, two applications of the method are presented, which capture very important aspects of information access: information browsing and query result ranking.
We consider a general form of information sources, consisting of a set of objects classified by t... more We consider a general form of information sources, consisting of a set of objects classified by terms arranged in a taxonomy. The query-based access to the information stored in sources of this kind, is plagued with uncertainty, due, among other things, to the possible linguistic mismatch between the user and the object classification. To overcome this uncertainty in all situations in which the user is not finding the desired information and is not willing or able to state a new query, the study proposes to extend the classification, in a way that is as reasonable as possible with respect to the original one. By equating reasonableness with logical implication, the sought extension turns out to be an explanation of the classification, captured by abduction. The problem of query evaluation on information sources extended in this way is studied and a polynomial time algorithm is provided for the general case, in which no hypothesis is made on the structure of the taxonomy. The algorithm is successively specialized on a most common kind of information sources, namely sources whose taxonomy can be represented as a directed acyclic graph. It is shown that query evaluation on extended sources is easier for this kind of sources. Finally, two applications of the method are presented, which capture very important aspects of information access: information browsing and query result ranking.
In this study we address the problem of answering queries over a peer-to-peer system of taxonomyb... more In this study we address the problem of answering queries over a peer-to-peer system of taxonomybased sources. A taxonomy states subsumption relationships between negation-free DNF formulas on terms and negation-free conjunctions of terms. To the end of laying the foundations of our study, we first consider the centralized case, deriving the complexity of the decision problem and of query evaluation. We conclude by presenting an algorithm that is efficient in data complexity and is based on hypergraphs. More expressive forms of taxonomies are also investigated which however lead to intractability. We then move to the distributed case, and introduce a logical model of a network of taxonomy-based sources. On such network, a distributed version of the centralized algorithm is then presented, based on a message passing paradigm, and its correctness is proved. We finally discuss optimization issues, and relate our work to the literature.
Searching the Web can be frustrating if the sought information is not related to a well defined a... more Searching the Web can be frustrating if the sought information is not related to a well defined and popular topic of interest or supplied by renowned Web Sites. One of the main goal of the activities in the area of the Semantic Web is to overcome this problem. The Digital Library (DL) arena is a suitable place to take up the challenge. The growing interest in the Digital Libraries along with the publishing of generalized software that simplifies the building of such systems, has recently improved the standardization of concept and functionalities of DLs, DL Systems and DL Management Systems (DLMS). A significant contribution in this area has been given by EU-funded projects in this area, namely DELOS, BRICKS and DILIGENT. This paper describes the Query Manager of the BRICKS-DLMS, which implements a distributed information retrieval capability, offered in the form of simple search (Google-like) or of advanced search, the latter based on knowledge represented by metadata coming from different schemas. Cross-language discovery, and personalized query and query results, based on user profiles, are other significant characteristics of BRICKS-DLMS Query Manager.
The paper presents an overview of the user generated content service that the ASSETS Best Practic... more The paper presents an overview of the user generated content service that the ASSETS Best Practice Network has designed, implemented and evaluated 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 aim of the BRICKS project is to design, develop and maintain an open user and service-oriente... more The aim of the BRICKS project is to design, develop and maintain an open user and service-oriented infrastructure to share knowledge and resources in the Cultural Heritage domain. Typical usage scenarios are integrated queries among several knowledge resource, e.g. to discover all Italian artifacts from renaissance in the European museums or to follow the life cycle of historic documents. These examples are specific applications, which are running on top of the BRICKS infrastructure. The BRICKS infrastructure will use the Internet as a backbone and will fulfil the requirements of expandability, graduality of engagement, scalability, availability, and interoperability.
Digital Library (DL) interoperability, as it is being reported in the DL.org Digital Library Refe... more Digital Library (DL) interoperability, as it is being reported in the DL.org Digital Library Reference Model, is intimately related to function interoperability. A prerequisite for the later is an appropriate function description, publication and discovery mechanisms. The importance of a framework which accommodates the specification of key DL function characteristics such as interface, behavior, dependencies and semantics, has been highlighted by the DL.org Functionality working group. Such a framework should be used in appropriate registries, which cater for the publication and discovery of DL functionality. In this paper we report the findings of the DL.org Functionality working group in terms of a DL function description framework and a set of contemporary registries that can serve as the basis for the provision of a DL Function interoperability enabling registry.
... in 1973 Founding and Former Series Editors: Gerhard Goos, Juris Hartmanis, and Jan van Leeuwe... more ... in 1973 Founding and Former Series Editors: Gerhard Goos, Juris Hartmanis, and Jan van Leeuwen Editorial Board David Hutchison Lancaster ... 348 Ilyes Jenhani, Nahla Ben Amor, Salem Benferhat, and Zied Elouedi Towards a Logic for Abstract MetaFinite State Machines ...
Proceedings of the 1st International Workshop on Collaborative Annotations in Shared Environment metadata, vocabularies and techniques in the Digital Humanities - DH-CASE '13, 2013
We present a model for complex documents possibly consisting of a hierarchically structured set o... more We present a model for complex documents possibly consisting of a hierarchically structured set of images or texts. Documents are represented both at the form level (as sets of physical features of the representing objects), at the content level (as sets of properties of the represented entities), and at the structure level. A uniform and powerful query language allows queries to be issued that transparently combine features pertaining to form, content and structure alike. Queries are expressions of a (fuzzy) logical language. While that part of the query that pertains to (medium-independent) content is "directly" processed by an inferential engine, that part that pertains to (medium-dependent) form is entrusted to specialised document processing procedures linked to the logical language by a procedural attachment mechanism. The model thus combines the power of state-of-the-art document processing techniques with the advantages of a clean, logically defined framework for understanding multimedia document retrieval.
Proceedings of the 16th annual international ACM SIGIR conference on Research and development in information retrieval - SIGIR '93, 1993
According to the logical model of Information Retrieval (IR), the task of IR can be described as ... more 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
Proceedings of the 18th annual international ACM SIGIR conference on Research and development in information retrieval - SIGIR '95, 1995
Images are a communication medium, hence objects of a linguistic nature having a form and a conte... more Images are a communication medium, hence objects of a linguistic nature having a form and a content. The form of an image is the image appearance and is understood as depicting a scene, the image content. The relationship between the form of an image and its content is established through a process of interpretation, capturing the meaning of the image form. Any information need on images can, and indeed has to, be seen as addressing either the image form, or its content, or the relationship between them. Consequently, any general, domain independent image retrieval facility should be based on a model supporting all these aspects of images. An image retrieval model, based on classical logic, is proposed which fulfills this basic requirement.
A taxonomy-based source consists of a taxonomy and a database storing objects that are indexed in... more A taxonomy-based source consists of a taxonomy and a database storing objects that are indexed in terms of the taxonomy. For this kind of sources, we describe a flexible interaction scheme that allows users to retrieve the objects of interest without having to be familiar with the terms of the taxonomy or with the supported query language. Specifically we describe an interaction manager whose functionality unifies several well-known interaction schemes including query by example, answer enlargement/reduction, query relaxation/restriction, index relaxation/contraction, feedback and adaptation mechanisms.
Uploads
Papers by C. Meghini