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PUBLICATIONS

2006

Large-scale distributed environments, where each node is completely autonomous and offers services to its peers through external communication, pose significant challenges to query processing and…
In this paper we describe briefly three systems: onCue a desktop internet-access toolbar, Snip!t a web-based bookmarking application and ontoPIM an ontology-based personal task-management system.…
This book constitutes the refereed proceedings of the 10th International Conference on Extending Database Technology, EDBT 2006, held in Munich, Germany, in March 2006. The 60 revised research papers…
Wide spread use of database systems in modern society has brought the need to provide inexperienced users with the ability to easily search a database with no specific knowledge of a query language…
This book constitutes the refereed proceedings of the 10th International Conference on Extending Database Technology, EDBT 2006, held in Munich, Germany, in March 2006. The 60 revised research…
The traditional interaction mechanism with a database system is through the use of a query language, the most widely used one being SQL. However, when one is facing a situation where he or she has…
Nowadays, our personal computer contains a huge amount of information, that is stored in several different formats. When looking for an information, one possibility is to use a keyword-based search…

2005

Personalization of keyword searches has attracted interest in the research community as a means to decrease search ambiguity and return results that are more bound to be interesting to a particular…
Personal Information Management (PIM) aims to support users in the collection, storage and retrieval of their personal information. In such a framework the focus is mainly on how better to handle…
The DELOS network of excellence is a European initiative that has been funded by the European Commission under its fifth and sixth framework programs. It has played a significant role in the…
Database needs are changing, driven by the Internet and increasing amounts of scientific and sensor data. In this article, the authors propose research into several important new directions for…
Query Personalization is the process of dynamically enhancing a query with related user preferences stored in a user profile with the aim of providing personalized answers. The underlying idea is…
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…
Personalization is a powerful mechanism that helps users to cope with the abundance of information on the Web. Database query personalization achieves this by dynamically constructing queries that…
Heuristic search is a core area of Artificial Intelligence and the employment of an efficient search algorithm is critical to the performance of an intelligent system. This paper addresses a…
This paper charts a research agenda on systems-oriented issues in digital libraries. It focuses on the most central and generic system issues, including system architecture, user-level…
Conventional data management occurs primarily in centralized servers or in well-interconnected distributed systems. These are removed from their end users, who interact with the systems mostly…
In today’s knowledge-driven society, information abundance and personal electronic device ubiquity have made it difficult for users to find the right information at the right time and at the right…
Digital libraries constitute a relatively young scientific field whose life spans roughly the last 10 years. Despite its youth, the field has made a long journey from its initial conception to the…

2004

In large statistical and scientific data management environments, where mediation architectures are used to integrate disparate and autonomous systems, a new problem - self-deadlock - may cause…
The rapid adoption of XML as the standard for data representation and exchange foreshadows a massive increase in the amounts of XML data collected, maintained, and queried over the Internet or in…
Query Personalization is the process of dynamically enhancing a query with related user preferences stored in a user profile with the aim of providing personalized answers. The underlying idea is…
Twig queries represent the building blocks of declarative query languages over XML data. A twig query describes a complex traversal of the document graph and generates a set of element tuples based…
Large-scale distributed environments, where each node is completely autonomous and offers services to its peers through external communication, pose significant challenges to query processing and…
As information becomes available in increasing amounts to a wide spectrum of users, the need for a shift towards a more user-centered information access paradigm arises. We develop a…
In this paper we present a distributed query framework suitable for use in federations of digital libraries (DL). Inspired by e-commerce technology, we recognize CPU-processing and queries (and…
Searching a digital library is typically a tedious task. A system can improve information access by building on knowledge about a user acquired in a user profile in order to customize information…
The last decade has seen unprecedented advances in network and distributed-system technologies, which have opened up the way for the construction of global-scale systems based on completely new…
We present a technique that is based on volatile mapping objects and enables wrappers-based mediation architectures to describe bi-directional (read–write) interschema mappings of multiple,…

2003

A system for the effective resource scheduling of composite multimedia objects involves a sequence packing formulation of the composite object scheduling problem and associated efficient algorithms…
The history of histograms is long and rich, full of detailed information in every step. It includes the course of histograms in di erent scienti c elds, the successes and failures of histograms in…
A group of senior database researchers gathers every few years to assess the state of database research and to point out problem areas that deserve additional focus. This report summarizes the…
A preliminary study of the issues surrounding a seach engine for Grid environments, GRISEN, that would enable the provision of a variety of Grid information services, such as locating useful…
The need for approximations of information has become very critical in the recent past. From traditional query optimization to newer functionality like user feedback and knowledge discovery, data…
Speculation is an every day phenomenon whereby one acts in anticipation of particular conditions that are likely to hold in the future. Computer science research has seen many successfull…

2002

Multimedia applications require a guaranteed level of service for accessing continuous-media data. To obtain such guarantees, the database server where the data are residing must employ an…

2000

Conventional histograms are `static' since they cannot be updated but only recalculated. In this paper, we introduce a `dynamic' version of V-optimal histograms, which is constructed and maintained…

1999

Answering queries approximately has recently been proposed as a way to reduce query response times in on-line decision support systems, when the precise answer is not necessary or early feedback is…
A range-sum query sums over all selected cells of an OLAP data cube where the selection is specified by ranges of contiguous values for each dimension. An efficient approach to process such queries…
The concept of two schemas being equivalent is fundamental to database design, schema integration, and data model translation. An important notion of schema equivalence, query equivalence, was…
Bitmap indexes are useful in processing complex queries in decision support systems, and they have been implemented in several commercial database systems. A key design parameter for bitmap indexes…
The NSF Invitational Workshop on Distributed Information, Computation, and Process Management for Scientific and Engineering Environments (DICPM) brought together domain specialists from…
It is almost twenty years after the 1st SSDBM was held in Berkeley (then called Workshop on Statistical Database Management). It is almost ten years after the first of a few workshops organized by…
This is probably the paper that opened the gates for several generic computer optimization techniques that were inspired by optimization processes found in nature. This one introduced Simulated…

1998

Scheduling algorithms for composite multimedia presentations need to ensure that the user-defined synchronization constraints for the various presentation components are met. This requirement gives…
In several working environments, production involves repeated executions of certain procedures. A workflow describes the individual tasks performed in these procedures and their interrelationships…
Bitmap indexing has been touted as a promising approach for processing complex adhoc queries in read-mostly environments, like those of decision support systems. Nevertheless, only few possible…
Multimedia applications require a guaranteed level of service for accessing Continuous Media (CM) data, such as video and audio. To obtain such guarantees, the database server whom the data is…