2139 result(s)
Page Size: 10, 20, 50
Export: bibtex, xml, json, csv
Order by:

CNR Author operator: and / or
more
Typology operator: and / or
Language operator: and / or
Date operator: and / or
more
Rights operator: and / or
2011 Conference object Unknown

Fuzzy ontologies and fuzzy integrals
Bobillo F., Straccia U.
Fuzzy ontologies extend classical ontologies to allow the representation of imprecise and vague knowledge. Although a relatively important amount of work has been carried out in the last years and they have been successfully used in several applications, several notions from fuzzy logic, such as fuzzy integrals, have not been considered yet in fuzzy ontologies. In this work, we show how to support fuzzy integrals in fuzzy ontologies. As a theoretical formalism, we provide the syntax and semantics of a fuzzy Description Logic with fuzzy integrals. We also provide a reasoning algorithm for a family of fuzzy integrals and show how to encode them into the language Fuzzy OWL 2.Source: 11th International Conference on Intelligent Systems Design and Applications, ISDA-11, pp. 1311–1316, Cordoba, Spain, 22-24 November 2011
DOI: 10.1109/ISDA.2011.6121841

See at: DOI Resolver | CNR People


2012 Other Unknown

PandAE Guida per l'Ufficio Personale
Diciotti R., Panichi G.
The system PandAE is a web application integrated with the detection time found in areas or in institutions. Allows the office staff of the Institute to obtain data on absences and presences of employees in a timely and accurate to perform their management functions.

See at: CNR People


2007 Article Open Access OPEN

Series of Workshops on Digital Library Foundations
Castelli D., Fox E.
This document presents the results of the workshop on "Foundations of Digital Libraries" held in connection with the ACM-IEEE JCDL 2007 Conference in June in Vancouver. The papers presented during the workshop aimed to contribute to laying the foundations for digital libraries as a whole, as well as continuing the work on the definition of a Reference Model for Digital Libraries that was launched by the EU DELOS Network of Excellence on Digital Libraries.Source: D-Lib magazine 13 (2007): 9–10. doi:10.1045/september2007-castelli
DOI: 10.1045/september2007-castelli

See at: D-Lib Magazine Open Access | DOI Resolver | CNR People | www.dlib.org


2005 Conference object Unknown

Digital Libraries over the Grid: Heaven or Hell?.
Castelli D., Ioannidis Y.
The last decade has seen unprecedented advances in network and distributedsystem technologies, which have opened up the way for the construction of globalscale systems based on completely new conceptions of computation and sharing of resources. The dream of integrating unlimited levels of processing power, unlimited amounts of information, and an unlimited variety of services, and o.ering the entire package in a reliable and seamless fashion to widely distributed users is quickly becoming reality. As Digital Libraries move towards more usercentric, pro-active, collaborative functionality and application diversity, they should be among the first to take advantage of such environments. The long-term vision of the field for creating Dynamic Universal Knowledge Environments calls for intensive computation and processing of very large amounts of information, hence, the needs for the appropriate distributed architecture are pressing.Source: ECDL 2005 - 9th European Conference on Digital Libraries (Vienna, Austria, 18-23 September 2005), pp. 477–478, Vienna, 18-23 September 2005

See at: CNR People


2014 Conference object Unknown

Going beyond research communication and management current practices
Castelli D.
This key note presentation discusses the impact of data-driven science in the research "landscape" and describes the functionality of the OpenAIRE infrastructure for research.Source: CRIS 2014 - 12th International Conference of Current Research Information Systems, Roma, Italy, 13-15 May 2014
Project(s): OPENAIREPLUS via OpenAIRE

See at: CNR People | www.cris2014.org


2002 Article Unknown

Integrated Performance Models for SPMD Applications and MIMD Architectures
Cremonesi P., Gennaro C.
This paper introduces queuing network models for the performance analysis of SPMD applications executed on generalpurpose parallel architectures such as MIMD and clusters of workstations. The models are based on the pattern of computation, communication, and I/O operations of typical parallel applications. Analysis of the models leads to the definition of speedup surfaces which capture the relative influence of processors and I/O parallelism and show the effects of different hardware and software components on the performance. Since the parameters of the models correspond to measurable program and hardware characteristics, the models can be used to anticipate the performance behavior of a parallel application as a function of the target architecture (i.e., number of processors, number of disks, I/O topology, etc).Source: IEEE transactions on parallel and distributed systems (Print) 13 (2002): 1320–1332. doi:10.1109/TPDS.2002.1158268
DOI: 10.1109/TPDS.2002.1158268

See at: DOI Resolver | ieeexplore.ieee.org | CNR People


2002 Article Open Access OPEN

Machine learning in automated text categorisation
Sebastiani F.
The automated categorization (or classification) of texts into predefined categories has witnessed a booming interest in the last 10 years, due to the increased availability of documents in digital form and the ensuing need to organize them. In the research community the dominant approach to this problem is based on machine learning techniques: a general inductive process automatically builds a classifier by learning, from a set of preclassified documents, the characteristics of the categories. The advantages of this approach over the knowledge engineering approach (consisting in the manual definition of a classifier by domain experts) are a very good effectiveness, considerable savings in terms of expert labor power, and straightforward portability to different domains. This survey discusses the main approaches to text categorization that fall within the machine learning paradigm. We will discuss in detail issues pertaining to three different problems, namely, document representation, classifier construction, and classifier evaluation.Source: ACM computing surveys 34 (2002): 1–47. doi:10.1145/505282.505283
DOI: 10.1145/505282.505283

See at: arXiv.org e-Print Archive Open Access | DOI Resolver | CNR People


2004 Article Unknown

A signature-based Approach for efficient relationship search on XML data collections
Amato G., Debole F., Rabitti F., Savino P., Zezula P.
We study the problem of finding relevant relationships among user defined nodes of XML documents. We define a language that determines the nodes as results of XPath expressions. The expressions are structured in a conjunctive normal form and the relationships among nodes qualifying in different conjuncts are determined as tree twigs of the searched XML documents. The query execution is supported by an auxiliary index structure called the tree signature. We have implemented a prototype system that supports this kind of searching and we have conducted numerous experiments on XML data collections. We have found the query execution very efficient, thus suitable for on-line processing. We also demonstrate the superiority of our system with respect to a previous, rather restricted, approach of finding the lowest common ancestor of pairs of XML nodes.Source: Lecture notes in computer science 3186 (2004): 82–96. doi:10.1007/978-3-540-30081-6_7
DOI: 10.1007/978-3-540-30081-6_7

See at: DOI Resolver | CNR People | www.springerlink.com


2004 Conference object Unknown

A unifying framework for flexible information access in taxonomy-based sources
Tzitzikas Y., Meghini C., Spyratos N.
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.Source: International Conference On Flexible Query Answering Systems (FQAS), pp. 161–174, Lyon, France, June 2004

See at: CNR People


2004 Article Unknown

Cross-language evaluation forum: objectives, results, achievements
Braschler M., Peters C.
The Cross-Language Evaluation Forum (CLEF) is now in its fourth year of activity. We summarize the main lessons learned during this period, outline the state-of-the-art of the research reported in the CLEF experiments and discuss the contribution that this initiative has made to research and development in the multilingual information access domain. We also make proposals for future directions in system evaluation aimed at meeting emerging needs.Source: Information retrieval (Boston) 7 (2004): 7–31.

See at: CNR People


2004 Conference object Unknown

Querying articulated sources
Meghini C., Tzitzikas Y.
In this study we address the problem of answering queries over information sources storing objects which are indexed by terms arranged in a taxonomy. We examine query languages of different expressivity and sources with different kinds of taxonomies. In the simplest kind, the taxonomy includes just term-to-term subsumption links. This case is used as a basis for further developments, in which we consider taxonomies consisting of term-to-queries links. An algorithm for query evaluation is presented for this kind of taxonomies, and it is shown that the addition of negation to the query language leads to intractability. Finally, query-to-query taxonomies are considered.Source: ODBASE 2004, International Conference on Ontologies, Databases and, pp. 945–962, Agia Napa, Cyprus, October 2004

See at: CNR People


2004 Conference object Unknown

Towards a generalized interaction scheme for information access
Tzitzikas Y., Meghini C., Spyratos N.
We introduce the formal framework of a generalized interaction scheme for information access between users and information sources. Within this framework we describe an interaction manager which supports more complex interaction schemes than those that are supported by existing systems, including: query by example, answer enlargement/reduction, query relaxation/restriction, index relaxation/contraction, 'relevance' feedback, and adaptation facilities. We give the foundations of this interaction manager from a mathematical point of view, in terms of an abstract view of an information source.Source: International Symposium on Foundations of Information and Knowledge, pp. 291–301, Vienna, Austria, 2-17 February

See at: CNR People


2004 Conference object Unknown

Transforming fuzzy description logics into classical description logics
Straccia U.
In this paper we consider Description Logics (DLs), which are logics for managing structured knowledge, with a well-known fuzzy extension to deal with vague information. While for fuzzy DLs ad-hoc, tableaux-like reasoning procedures have been given in the literature, the topic of this paper is to present a reasoning preserving transformation of fuzzy DLs into classical DLs. This has the considerable practical consequence that reasoning in fuzzy DLs is feasible using already existing DL systems.Source: Logics in Artificial Intelligence, 9th European Conference, pp. 385–399, Lisbon, Portugal, September, 2004
DOI: 10.1007/978-3-540-30227-8_33

See at: DOI Resolver | link.springer.com | CNR People


2005 Conference object Unknown

sPLMap: A probabilistic approach to schema matching
Nottelmann H., Straccia U.
This paper introduces the first formal framework for learning mappings between heterogeneous schemas, which is based on probabilistic logics. This task, also called ``schema matching'', is a crucial step in integrating heterogeneous collections. As schemas may have different granularities, and as schema attributes do not always match precisely, a general-purpose schema mapping approach requires support for uncertain mappings, and mappings have to be learned automatically. The framework combines different classifiers for finding suitable mapping candidates (together with their weights), and selects that set of mapping rules which is the most likely one. Finally, the framework with different variants has been evaluated on two different data sets.Source: Advances in Information Retrieval, 27th European Conference on IR Research, pp. 81–95, March 2005
DOI: 10.1007/978-3-540-31865-1_7

See at: DOI Resolver | link.springer.com | CNR People


2005 Article Unknown

Any-world assumptions in logic programming
Loyer Y., Straccia U.
Due to the usual incompleteness of information representation, any approach to assign a semantics to logic programs has to rely on a default assumption on the missing information. The emph{stable model semantics}, that has become the dominating approach to give semantics to logic programs, relies on the Closed World Assumption (CWA), which asserts that by default the truth of an atom is emph{false}. There is a second well-known assumption, called emph{Open World Assumption} (OWA), which asserts that the truth of the atoms is supposed to be emph{unknown} by default. However, the CWA, the OWA and the combination of them are extremal, though important, assumptions over a large variety of possible assumptions on the truth of the atoms, whenever the truth is taken from emph{an arbitrary truth space}. The topic of this paper is to allow emph{any} assignment (ie interpretation), over a truth space, to be a default assumption. Our main result is that our extension is conservative in the sense that under the ``everywhere false' default assumption (CWA) the usual stable model semantics is captured. Due to the generality and the purely algebraic nature of our approach, it abstracts from the particular formalism of choice and the results may be applied in other contexts as well.Source: Theoretical computer science 342 (2005): 351–381.

See at: CNR People


2005 Article Unknown

From heterogeneous information spaces to virtual documents
Candela L., Castelli D., Pagano P., Simi M.
This paper introduces DoMDL, a powerful and flexible document model capable to represent multi-edition, structured, multimedia documents that can be disseminated in multiple manifestation formats. This model also allows any document to be associated with multiple metadata descriptions in different formats and to include semantic relationships with other documents and parts of them. The paper discusses also how the OpenDLib Digital Library Management System exploits this model to abstract from the specific organization and structure of the documents that are imported from different heterogeneous information sources in order to provide virtual documents that fulfill the needs of the different DL user communities.Source: Lecture notes in computer science 3815 (2005): 11–22. doi:10.1007/11599517_2
DOI: 10.1007/11599517_2

See at: DOI Resolver | link.springer.com | CNR People


2005 Conference object Unknown

Query answering in normal logic programs under uncertainty
Straccia U.
We present a simple, yet general top-down query answering procedure for normal logic programs over lattices and bilattices, where functions may appear in the rule bodies. Its interest relies on the fact that many approaches to paraconsistency and uncertainty in logic programs with or without non-monotonic negation are based on bilattices or lattices, respectively.Source: 8th European Conference on Symbolic and Quantitative Approaches to Reasoning with Uncertainty, pp. 687–700, Barcellona, Spain, July 2005
DOI: 10.1007/11518655_58

See at: DOI Resolver | link.springer.com | CNR People


2005 Part of book or chapter of book Unknown

Moving digital library service systems to the Grid
Candela L., Castelli D., Pagano P., Simi M.
The architecture of a digital library service system strongly influences its capabilities. In this paper we report on our experience with a distributed digital library system, OpenDLib, and we describe why, in the attempt to better satisfy the user requirements, we decided to develop DILIGENT, a service-oriented digital library infrastructure on the Grid. The paper describes and compare the two systems by focusing, in particular, on that part of the architecture that controls and supplies the necessary features for creating and managing digital libraries.Source: Peer-to-Peer, Grid, and Service-Orientation in Digital Library Architectures, edited by Can Türker; Maristella Agosti; Hans-Jörg Schek, pp. 236–259. WIEN: SPRINGER-VERLAG, 2005
DOI: 10.1007/11549819_15

See at: DOI Resolver | CNR People


2005 Conference object Unknown

Towards a fuzzy description logic for the semantic Web (preliminary report)
Straccia U.
In this paper we present a fuzzy version of ${cal SHOIN}(D)$, the corresponding Description Logic of the ontology description language OWL DL. We show that the representation and reasoning capabilities of fuzzy SHOIN(D) go clearly beyond classical SHOIN(D). We present its syntax and semantics. Interesting features are that concrete domains are fuzzy and entailment and subsumption relationships may hold to some degree in the unit interval [0,1].Source: The Semantic Web: Research and Applications, Second European Semantic Web Conference, pp. 167–181, 2nd European Semantic Web Conference, 29 May - 1 June 2005
DOI: 10.1007/11431053_12

See at: DOI Resolver | link.springer.com | CNR People


2005 Conference object Unknown

Uncertainty management in logic programming: simple and effective top-down query answering
Straccia U.
We present a simple, yet general top-down query answering procedure for logic programs managing uncertainty. The main features are: ii{i} the certainty values are taken from a certainty lattice; ii{ii} computable functions may appear in the rule bodies to manipulate certainties; and ii{iii} we solve the problem by a reduction to an equational systems, for which we device a top-down procedure.Source: Knowledge-Based Intelligent Information and Engineering Systems, 9th International Conference, pp. 753–760, Melbourne, Australia, 14-16 September 2005
DOI: 10.1007/11552451_103

See at: DOI Resolver | link.springer.com | CNR People