Catálogo de publicaciones - libros

The similarity search has become a fundamental computational task in many applications. One of the mathematical models of the similarity – the metric space – has drawn attention of many researchers resulting in several sophisticated metric-indexing techniques. An important part of a research in this area is typically a prototype implementation and subsequent experimental evaluation of the proposed data structure. This paper describes an implementation framework called MESSIF that eases the task of building such prototypes. It provides a number of modules from basic storage management, over a wide support for distributed processing, to automatic collecting of performance statistics. Due to its open and modular design it is also easy to implement additional modules, if necessary. The MESSIF also offers several ready-to-use generic clients that allow to control and test the index structures.

Image similarity is typically evaluated by using low level features such as color histograms, textures, and shapes. Image similarity search algorithms require computing similarity between low level features of the query image and those of the images in the database. Even if state of the art access methods for similarity search reduce the set of features to be accessed and compared to the query, similarity search has still an high cost.

In this paper we present a novel approach which processes image similarity search queries by using a technique that takes inspiration from text retrieval. We propose an approach that automatically indexes images by using visual terms chosen from a visual lexicon.

Each visual term represents a typology of visual regions, according to various criteria. The visual lexicon is obtained by analyzing a training set of images, to infer which are the relevant typology of visual regions. We have defined a weighting and matching schema that are able respectively to associate visual terms with images and to compare images by means of the associated terms.

We show that the proposed approach do not lose performance, in terms of effectiveness, with respect to other methods existing in literature, and at the same time offers higher performance, in terms of efficiency, given the possibility of using inverted files to support similarity searching.

A reference architecture for a given domain provides an architectural template which can be used as a starting point for designing the software architecture of a system in that domain. Despite the popularity of tools and systems commonly termed “Digital Library”, very few attempts exist to set the foundation governing their development thus making integration and reuse of third party assets and results very difficult. This paper presents a reference architecture for the Digital Library domain characterised by many, multidisciplinary and distributed players, both resource providers and consumers, whose requirements evolve along the time. The paper validates this reference architecture by describing the structure of two current systems, and , facing the problem to deliver large-scale digital libraries in two different contexts and with diverse technologies.

DelosDLMS is a prototype of a next-generation Digital Library (DL) management system. It is realized by combining various specialized DL functionalities provided by partners of the DELOS network of excellence. Currently, DelosDLMS combines text and audio-visual searching, offers new information visualization and relevance feedback tools, provides novel interfaces, allows retrieved information to be annotated and processed, integrates and processes sensor data streams, and finally, from a systems engineering point of view, is easily configured and adapted while being reliable and scalable. The prototype is based on the OSIRIS/ISIS platform, a middleware environment developed by ETH Zürich and now being extended at the University of Basel.

Future information spaces such as Digital Libraries require new infrastructures that allow to use and to combine various kinds of functions in a unified and reliable way. The paradigm of service-oriented architectures (SoA) allows providing application functionality in a modular, self-contained way and to individually combine this functionality. The paper presents the ISIS/OSIRIS system which consists of a generic infrastructure for the reliable execution of distributed service-based applications (OSIRIS) and a set of dedicated Digital Library application services (ISIS) that provide, among others, content-based search in multimedia collections.

We present a solution to the problem of sharing metadata between different archives spread across a geographic region. In particular we consider the Italian Veneto Region archives. Initially we analyze the Veneto Region information system based on a domain gateway system called “SIRV-INTEROP project” and we propose a solution to provide advanced services against the regional archives. We deal with these issues in the context of the SIAR – Regional Archival Information System – project.

The aim of this work is to integrate different archive realities in order to provide unique public access to archival information. Moreover we propose a non-intrusive, flexible and scalable solution that preserves archives identity and autonomy.

Data Stream Management (DSM) addresses the continuous processing of sensor data. DSM requires the combination of stream operators, which may run on different distributed devices, into stream processes. Due to the recent advantages in sensor technologies and wireless communication, the amount of information generated by DSM will increase significantly. In order to efficiently deal with this streaming information, Digital Library (DL) systems have to merge with DSM systems. Especially in healthcare, the continuous monitoring of patients at home (telemonitoring) will generate a significant amount of information stored in an e-health digital library (electronic patient record). In order to stream-enable DL systems, we present an integrated data stream management and Digital Library infrastructure in this work. A vital requirement for healthcare applications is however that this infrastructure provides a high degree of reliability. In this paper, we present novel approaches to reliable DSM within a DL infrastructure. In particular, we propose information filtering operators, a declarative query engine called MXQuery, and efficient operator checkpointing to maintain high result quality of DSM. Furthermore, we present a demonstrator implementation of the integrated DSM and DL infrastructure, called OSIRIS-SE. OSIRIS-SE supports flexible and efficient failure handling to ensures complete and consistent continuous data stream processing and execution of DL processes even in the case of multiple failures.

This paper describes the possible use of advanced recommendation methods in the area of Digital Libraries. Content-based recommenders analyze documents previously rated by a target user, and build a profile exploited to recommend new interesting documents. One of the main limitations of traditional keyword-based approaches is that they are unable to capture the semantics of the user interests, due to the natural language ambiguity. We developed a semantic recommender system, called ITem Recommender, able to disambiguate documents before using them to learn the user profile. The Conference Participant Advisor service relies on the profiles learned by ITem Recommender to build a personalized conference program, in which relevant talks are highlighted according to the participant’s interests.

In this paper we present CoCoMA, an integrated platform, developed in the framework of the DELOS II European Network of Excellence on Digital Libraries, aiming at the unification of the most important aspects of multimedia management and multimedia presentation. The paramount goal of CoCoMA is to maximize the added value from task and data integration by the identification and exploitation of connection points and inherent workflow similarities. The paper provides a brief description of the involved research fields, suggests an architecture for integrated multimedia consumption and presentation, and discusses the most prominent connection points. Problems and solutions are discussed jointly, and illustrated by the components of the application prototype developed for the DELOS project.

In this paper, a general methodology for gathering and mining information from Web log files is proposed. A series of tools to retrieve, store, and analyze the data extracted from log files have been designed and implemented. The aim is to form general methods by abstracting from the analysis of logs which use a well-defined standard format, such as the Extended Log File Format proposed by W3C. The methodology has been experimented on the Web log files of The European Library portal; the experimental analyses led to personal, technical, geographical and temporal findings about the usage and traffic load. Considerations about a more accurate tracking of users and users profiles, and a better management of crawler accesses using authentication are presented.