Digital Libraries are complex and advanced forms of information systems which extend and augment their physical counterparts by amplifying existing resources and services and enabling development of new kinds of human problem solving and expression. Their complexity arises from the data-rich domain of discourse as well as from extended demands for multi-disciplinary input, involving distributed systems architectures, structured digital documents, collaboration support, human-computer interaction, information filtering, etc. In addition to the broad range of technical issues, ethics and intellectual property rights add to the complication that is normally associated with the development, maintenance, and use of Digital Libraries. The Second European Conference on Digital Libraries (ECDL’98) builds upon the success of the first of this series of European Conferences on Research and Advanced Technology for Digital Libraries, held last year in Pisa, Italy, September 1-3, 1997. This series of conferences is partially funded by the TMR Programme of the European Commission and is actively supported and promoted by the European Research Consortium on Informatics and Mathematics (ERCIM). The aim is to bring together the different communities involved in the development of Digital Libraries, to review progress and to discuss strategies, research and technological development (RTD) issues, as well as specific topics related to the European context. These communities include professionals from universities, research centres, industry, government agencies, public libraries, etc.

Annotation Fourteen technical papers presented at the May 1997 meeting featuring the latest technical results and issues in digital libraries. The papers focus on digital library images (digital image indexing and retrieval, wavelet-based image indexing techniques), a discussion of digital libraries in Europe, specific library projects such as Columbia's digital news system, and new technologies for documents, information sources, and security. Includes illustrations. Lacks an index. Annotation copyrighted by Book News, Inc., Portland, OR.

ECDL 2002 was the 6th conference in the series of European Conferences on Research and Advanced Technologies for Digital Libraries. Following previous events in Pisa (1997), Heraklion (1998), Paris (1999), Lisbon (2000), and Da- stadt (2001), this year ECDL was held in Rome. ECDL 2002 contributed, - gether with the previous conferences, to establishing ECDL as the major - ropean forum focusing on digital libraries and associated technical, practical, and social issues. ECDL 2002 continued the tradition already established by the previous conferences in meeting the needs of a large and diverse constituency, which includes researchers, practitioners, educators, policy makers, and users. The focus of ECDL 2002 was on underlying principles, methods, systems, and tools to build and make available e?ective digital libraries to end users. Architecture, metadata, collection building, web archiving, web technologies,- books, OAI applications, preservation, navigation, query languages, audio video retrieval, multimedia-mixed media, user studies and evaluation, humanities, and digital libraries were some of the key issues addressed. An international Program Committee was set up composed of 61 members, with representatives from 25 countries. A total of 145 paper submissions, 15 poster submissions, and 18 proposals for demos were received. Each paper was evaluated by 3 referees and 42 full papers and 6 short papers of high quality were selected for presentation.

ECDL2000, the Fourth European Conference on Research and Advanced Te- nology for Digital Libraries, is being held this year in Lisbon, Portugal, following previous events in Pisa (1997), Heraklion (1998), and Paris (1999). One major goal of the ECDL conference series has been to draw information professionals, stakeholders, and user communities from both the research world and from - dustry into a discussion of the alternative technologies, policies, and scenarios for global digital libraries. The success of previous conferences makes them a hard act to follow. The eld of digital libraries draws on a truly diverse set of scienti c and technical disciplines. In the past three years, moreover, global cooperation on research and development has emerged as an urgent priority, particularly in the new European Framework Programme and in the Digital Library Initiative in the United States. Because of this diversity, the eld is perhaps still struggling for an identity. But this struggle for identity is itself a source of energy and creativity. P- ticipants in this eld feel themselves to be part of a special community, with special people. Each of us may claim expertise on a narrow issue, with speci c projects, but the choices we make and the methods we use in local solutions can have unforeseen impacts within a growing universe of interconnected resources.

Digital libraries (DLs) have introduced new technologies, as well as leveraging, enhancing, and integrating related technologies, since the early 1990s. These efforts have been enriched through a formal approach, e.g., the 5S (Societies, Scenarios, Spaces, Structures, Streams) framework, which is discussed in two earlier volumes in this series. This volume should help advance work not only in DLs, but also in the WWW and other information systems. Drawing upon four (Kozievitch, Murthy, Park, Yang) completed and three (Elsherbiny, Farag, Srinivasan) in-process dissertations, as well as the efforts of collaborating researchers and scores of related publications, presentations, tutorials, and reports, this book should advance the DL field with regard to at least six key technologies. By integrating surveys of the state-of-the-art, new research, connections with formalization, case studies, and exercises/projects, this book can serve as a computing or information science textbook. It can support studies in cyber-security, document management, hypertext/hypermedia, IR, knowledge management, LIS, multimedia, and machine learning. Chapter 1, with a case study on fingerprint collections, focuses on complex (composite, compound) objects, connecting DL and related work on buckets, DCC, and OAI-ORE. Chapter 2, discussing annotations, as in hypertext/hypermedia, emphasizes parts of documents, including images as well as text, managing superimposed information. The SuperIDR system, and prototype efforts with Flickr, should motivate further development and standardization related to annotation, which would benefit all DL and WWW users. Chapter 3, on ontologies, explains how they help with browsing, query expansion, focused crawling, and classification. This chapter connects DLs with the Semantic Web, and uses CTRnet as an example. Chapter 4, on (hierarchical) classification, leverages LIS theory, as well as machine learning, and is important for DLs as well as the WWW. Chapter 5, on extraction from text, covers document segmentation, as well as how to construct a database from heterogeneous collections of references (from ETDs); i.e., converting strings to canonical forms. Chapter 6 surveys the security approaches used in information systems, and explains how those approaches can apply to digital libraries which are not fully open. Given this rich content, those interested in DLs will be able to find solutions to key problems, using the right technologies and methods. We hope this book will help show how formal approaches can enhance the development of suitable technologies and how they can be better integrated with DLs and other information systems.

This book constitutes a carefully arranged selection of papers presented at the Forum on Research and Technology Advances in Digital Libraries, ADL'95, held in McLean, Virginia, USA in May 1995. Besides 15 revised refereed technical contributions, the book presents four invited survey papers by key persons heading institutions and projects essentially advancing the state of the art: France Cordova (NASA), James H. Billington (The Library of Congress), Raj Reddy (CMU), and Larry Smarr (NCSA, University of Illinois). The technical papers are organized in topical sections on visualization, document handling and information retrieval, network-based information and resource discovery, and design issues and prototyping.

This thesis deals with the problems of characterizing the semantics of and assuring efficient execution for database query languages, where the database contains semistructured and time-varying information. This area of technology is of much interest and significance for databases and knowledge bases; it also presents many challenging research problems deserving an in-depth investigation. Thus, the topic of Elisa Quintarelli's dissertation is well chosen and totally appropriate to the current research trends. In her thesis, Elisa addresses a number of related problems. However, her work and contributions concentrate on two main problems. The first is the definition of an effective graph-based approach to the formalization of query languages for semistructured and temporal information. In her approach, query execution is viewed as the process of matching the query graph with the database instance graph; therefore, query execution reduces to searching the database for subgraphs that are similar to the given query graph. The search for such matches can be supported through the computational process of biosimulation. This approach is used to de?ne the semantics of several languages, including graphical languages, such as G-Log and GraphLog, semistructured information languages, such as Lorel, and temporal languages, such as TSS-QL. Both graph-based approaches and biosimulation had been used by previous authors for defining query languages and their semantics; however, this work goes well beyond previous approaches by integrating and refining these techniques into a flexible and powerful paradigm that Elisa demonstrates to be effective on a spectrum of languages and a suite of alt- native semantics.