Sarantos Kapidakis

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Digital libraries (DLs) are new and innovative information systems, under constant development and change, and therefore evaluation is of critical importance to ensure not only their correct evolution but also their acceptance by the user and application communities. The Evaluation activity of the DELOS Network of Excellence has performed a large-scale(More)
Digital library interaction evaluation has, by nature, a user centered perspective, which directs the scientific research to the benefit of the user and narrows the research parameters. In this paper we propose a new framework for the evaluation of interaction and we introduce the concepts of usefulness, usability and performance as the main contributing(More)
This paper introduces SCENS, a Secure Content Exchange Negotiation System suitable for the exchange of private digital data that reside in distributed digital repositories. SCENS is an open negotiation system with flexibility, security and scalability. SCENS is currently being designed to support data sharing in scientific research, by providing incentives(More)
We compare the usage of a Digital Library with many different categories of collections, by examining its log files for a period of twenty months, and we conclude that the access points that the users mostly refer to, depend heavily on the type of content of the collection, the detail of the existing metadata and the target user group. We also found that(More)
This study aims to investigate the query formulation and reformulation patterns such as generalisations, specifications, parallel movements and replacements with synonyms within the search procedure. Results showed that users reformulated their queries by using terms contained in the retrieved results while in the query reformulation process they mainly(More)
Monolithic information system to effectively serve the needs of an entire healthcare organizational structure. Thus, information and telecommunications systems must primarily provide the infrastructure to support the effective integration of distributed and heterogeneous components, ensuring overall integrity in terms of functional and information(More)
Scientific repositories found in institutions and organizations consist of data and programs. Data consists principally of numeric data, images, and text documents. Programs consist principally of software methods for visualizing and processing data and simulators of natural processes. Data represents both measured physical behavior and the results of(More)
Collecting digital materials is time-consuming and can gain from automation. Since each source – and even each acquisition – may involve a separate negotiation of terms, a collector may prefer to use a broker to represent his interests with owners. This paper describes the Data Broker Framework (DBF), which is designed to automate the process of digital(More)
A graph of Access Points can be used as a tool in a number of applications such as, clarification and better understanding of their semantics and inter-relations, query transformations, more precise query formulation, etc. We apply a procedure to create a graph of the Access Points, according to their subset relationship, based on the official semantics of(More)