User-Oriented Authorization in Collaborative Environments

Access rights for collaborative systems tend to be rather complex, leading to difficulties in the presentation and manipulation of access policies at the user interface level. We confront a theoretical access rights model with the results of a field study which investigates how users specify access policies. Our findings suggest that our theoretical model addresses most of the issues raised by the field study, when the required functionality can be presented in an appropriate user interface

CollaborationBus: An Editor for the Easy Configuration of Complex Ubiquitous Environment

Early sensor-based infrastructures were often developed by experts with a thorough knowledge of base technology for sensing information, for processing the captured data, and for adapting the system’s behaviour accordingly. In this paper we argue that also end-users should be able to configure Ubiquitous Computing environments. We introduce the CollaborationBus application: a graphical editor that provides abstractions from base technology and thereby allows multifarious users to configure Ubiquitous Computing environments. By composing pipelines users can easily specify the information flows from selected sensors via optional filters for processing the sensor data to actuators changing the system behaviour according to the users’ wishes. Users can compose pipelines for both home and work environments. An integrated sharing mechanism allows them to share their own compositions, and to reuse and build upon others’ compositions. Real-time visualisations help them understand how the information flows through their pipelines. In this paper we present the concept, implementation, and early user feedback of the CollaborationBus application

CSCW - Four Characters in Search of a Context

The title of this paper was chosen to highlight the fact that the label CSCW, although widely adopted as the acronym for the field of Computer Supported Cooperative Work, has been applied to computer applications of very different ilk. It is not at all clear what are the unique identifying elements of this research area. This paper provides a framework for approaching the issue of cooperative work and its possible computer support. The core issues are identified and prospects for the field are outlined

The document synchronizer : a partial solution for real-time replication

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.Includes bibliographical references (leaf 41).by Ben H. Shih.M.Eng

Semantics-based locking:from isolation to cooperation

'Advanced database applications', such as CAD/CAM, CASE, large AI applications or imageand voice processing, place demands on transaction management which differ substantially from those of traditional database applications. In particular, there is a need to support 'enriched' data models (which include, for example, complex objects or version and configuration management), 'synergistic' cooperative work, and application- or user-supported consistency. This paper deals with a subset of these problems. It develops a methodology for implementing semantics-based concurrency control on the basis of ordinary locking. More specifically, it will be shown how conventional locking can step by step be improved and refined to finally reach our initial goal, namely a comprehensive support of synergistic cooperative work by the exploitation of application-specific semantics. In addition to the 'conventional' binding of locks to transactions we consider the binding of locks to objects (object related) and subjects (subject related locks). Object related locks can define persistent and adaptable access restrictions on objects. This permits, among others, the modeling of different types of version models (time versions, version graphs) as well as library (standard) objects. Subject related locks are bound to subjects (user, application, etc.) and can be used among others to supervise or direct the transfer of objects between transactions.<br/

Combining knowledge discovery, ontologies, annotations, and semantic wikis

Semantic Wikis provide an original and operational infrastructure for efficiently com- bining semantic technologies and collaborative design activities. This text presents: a running example and its context (organization of the collections in a museum); concepts of wikis as a tool to allow computer supported cooperative work (cscw); concepts of se- mantic technologies and knowledge representation; concepts and examples of semantic wikis; anatomy of a semantic wiki (reasoning tools, storage, querying); and research directions.Laboratorio de Investigación y Formación en Informática Avanzad

SCDAS - Decision Support System for Group Decision Making: Information Processing Issues

Most research in the field of computerized Group Decision Support System is devoted to the analysis and support of the quantitative phase of decision processes using various methods of multiple-criteria analysis. Experience shows that the soft side of the decision process also needs support. This relates mostly to the distribution of textual information that augments the quantitative side of the decision process and to provides the linkage between such information and numerical data. This aspect is especially important when the decision support system is implemented in a distributed computing environment. In this paper possible forms of information processed within the SCDAS system are analyzed and the framework for implementing the software that provides such processing functions is presented