Nuno Freire

A metadata geoparsing system for place name recognition and resolution in metadata records

This paper describes an approach for performing recognition and resolution of place names mentioned over the descriptive metadata records of typical digital libraries. Our approach exploits evidence provided by the existing structured attributes within the metadata records to support the place name recognition and resolution, in order to achieve better results than by just using lexical evidence from the textual values of these attributes. In metadata records, lexical evidence is very often insufficient for this task, since short sentences and simple expressions are predominant. Our implementation uses a dictionary based technique for recognition of place names (with names provided by Geonames), and machine learning for reasoning on the evidences and choosing a possible resolution candidate. The evaluation of our approach was performed in data sets with a metadata schema rich in Dublin Core elements. Two evaluation methods were used. First, we used cross-validation, which showed that our solution is able to achieve a very high precision of 0,99 at 0,55 recall, or a recall of 0,79 at 0,86 precision. Second, we used a comparative evaluation with an existing commercial service, where our solution performed better on any confidence level (p<0,001).

Geographically-aware information retrieval for collections of digitized historical maps

DIGMAP is a project focused on historical digitized maps. The project will develop a set of services, to be available in the Internet, based on reusable open-source software solutions. The main service will provide discovery and access to resources related to historical cartography, based on metadata from European national libraries and other relevant third part providers. These resources will comprise both physical and digitized objects. In the case of digitized maps, available metadata will be enriched by automatic and semi-automatic processes that will try to extract relevant indexing information from the images of the digitized maps, as also from any kind of associated text. This paper presents an early overview on the project, particularly focusing on the aspects related to geographical information retrieval.

FRBRization of MARC records in multiple catalogs

This paper addresses the problem of using the FRBR model to support the presentation of results. It describes a service implementing new algorithms and techniques for transforming existing MARC records into the FRBR model for this specific purpose. This work was developed in the context of the TELPlus project and processed 100,000 bibliographic and authority records from multilingual catalogs of 12 European countries.

An approach for named entity recognition in poorly structured data

This paper describes an approach for the task of named entity recognition in structured data containing free text as the values of its elements. We studied the recognition of the entity types of person, location and organization in bibliographic data sets from a concrete wide digital library initiative. Our approach is based on conditional random fields models, using features designed to perform named entity recognition in the absence of strong lexical evidence, and exploiting the semantic context given by the data structure. The evaluation results support that, with the specialized features, named entity recognition can be done in free text within structured data with an acceptable accuracy. Our approach was able to achieve a maximum precision of 0.91 at 0.55 recall and a maximum recall of 0.82 at 0.77 precision. The achieved results were always higher than those obtained with Stanford Named Entity Recognizer, which was developed for grammatically well-formed text. We believe this level of quality in named entity recognition allows the use of this approach to support a wide range of information extraction applications in structured data.

Identification of FRBR works within bibliographic databases: an experiment with UNIMARC and duplicate detection techniques

Many experiments and studies have been conducted on the application of FRBR as an implementation model for bibliographic databases, in order to improve the services of resource discovery and transmit better perception of the information spaces represented in catalogues. One of these applications is the attempt to identify the FRBR work instances shared by several bibliographic records. In our work we evaluate the applicability to this problem of techniques based on string similarity, used in duplicate detection procedures mainly by the database research community. We describe the particularities of the application of these techniques to bibliographic data, and empirically compare the results obtained with these techniques to those obtained by current techniques, which are based on exact matching. Experiments performed on the Portuguese national union catalogue show a significant improvement over currently used approaches.

REPOX: a framework for metadata interchange

This demonstration presents an XML framework for metadata interchange. REPOX has two goals: to be a means for libraries and other cultural institutions to provide OAI-PMH access to their metadata records, independently of their original format, with a tool that is easy to install, use and deploy; and to be used as an aggregator of OAI-PMH Data Sources. The records are stored internally in XML and there is a metadata transformation service that allows for translation to desired formats. This demonstration will show the usage scenarios, technologies and current results.

Exploring Comparative Evaluation of Semantic Enrichment Tools for Cultural Heritage Metadata

Semantic enrichment of metadata is an important and difficult problem for digital heritage efforts such as Europeana. This paper gives motivations and presents the work of a recently completed Task Force that addressed the topic of evaluation of semantic enrichment. We especially report on the design and the results of a comparative evaluation experiment, where we have assessed the enrichments of seven tools (or configurations thereof) on a sample benchmark dataset from Europeana.

Digital libraries and digitised maps: an early overview of the DIGMAP project

DIGMAP is a project to find solutions for digital libraries scenarios focused on digitised historical maps. The main service will reuse metadata from European national libraries and other relevant third party metadata sources to provide discovery and access to contents. This will also include a proof of concept of a scenario of reusing and enriching these metadata by automatic processes that will try to extract relevant indexing information from the images of the digitised maps, as well as from any kind of associated text.

Complex Data Transformations in Digital Libraries with Spatio-Temporal Information

The DIGMAP project researched automated methods for enriching metadata records with structured geo-temporal information. This paper presents our findings regarding the use of XML technology for expressing transformations between the different XML schemas used in DIGMAP metadata records and service interfaces. Both XSLT and XQuery are functional, declarative languages that effectively support XML data integration. They are also extensible, in the sense that new functions can be specified in Java and then combined with general XPath expressions. We extended an XSLT/Xquery engine with additional functions for processing spatio-temporal information and for dealing with incompleteness and inconsistencies in the data. The paper discusses the application over different XML formats and metadata standards.

BND: the architecture of a National Digital Library

We describes the architecture and components of the infrastructure in construction for the National Digital Library in Portugal. The requirements emerged from the definition of the services to support, with a special focus on scalability, and from the decision to give a special attention to community building standards, open solutions, and reusable and cost effective components. The generic bibliographic metadata format in this project is UNIMARC, and the structural metadata is METS. The URN identifiers are processed and resolved as simple but very effective PURL identifiers. The storage for immediate access is provided by the LUSTRE file system, and by ARCO, a locally developed GRID architecture, for long term preservation. All these components run on Linux servers, as also the middleware for access based in the FEDORA framework.