Benoît Otjacques

Identity Management and Data Sharing in the European Union

Citizens and enterprises in the European Union benefit from a common internal market and other freedoms. The resulting and growing mobility and cross-border collaboration necessity leads to specific challenges for e-Government applications. This article presents the results of a study run by Luxembourg’s Presidency of the EU during the first half of 2005. This study investigated one central aspect in this area: How do countries identify their citizens and businesses, and what are their national provisions regarding data protection and privacy that limit and regulate the sharing of such data? In more technical terms: What is the impact of identity management and related privacy issues on the interoperability of e-Government systems? The status quo in 18 member states is illustrated, and compared with the results of a similar study run in 2001. We present a general model for describing the framework of identity management in cross-border contexts.

CGD --- A New Algorithm to Optimize Space Occupation in Ellimaps

How to visualize datasets hierarchically structured is a basic issue in information visualization. Compared to the common diagrams based on the nodes-links paradigm (e.g. trees), the enclosure-based methods have shown high potential to represent simultaneously the structure of the hierarchy and the weight of nodes. In addition, these methods often support scalability up to sizes where trees become very complicated to understand. Several approaches belong to this class of visualization methods such as treemaps, ellimaps, circular treemaps or Voronoi treemaps. This paper focuses on the specific case of ellimaps in which the nodes are represented by ellipses nested one into each other. A controlled experiment has previously shown that the initial version of the ellimaps was efficient to support the perception of the dataset structure and was reasonably acceptable for the perception of the node weights. However it suffers from a major drawback in terms of display space occupation. We have tackled this issue and the paper proposes a new algorithm to draw ellimaps. It is based on successive distortions and relocations of the ellipses in order to occupy a larger proportion of the display space than the initial algorithm. A Monte-Carlo simulation has been used to evaluate the filling ratio of the display space in this new approach. The results show a significant improvement of this factor.

Cooperation indexes to support workspace awareness

Awareness is now acknowledged in the CSCW domain as an important element to take into account. This paper explores and refines the concept of workspace awareness. A categorization is proposed based on two criteria: the granularity and the ability to identify the cooperating entities. Two concepts are defined on this basis: Workspace Individual Awareness (WIA) and Workspace Global Awareness (WGA). New kinds of metrics are then described to support WGA and a prototype implementing WGA is shortly discussed.

Visualizing the activity of a web-based collaborative platform

This paper describes a prototype that offers visualization features for monitoring a Web-based collaborative platform. The data displayed supports workplace awareness by providing an overview of the activities carried out on the platform. The prototype focuses on the information structured as hierarchical data. Three views are included: a classic vertical tree, a treemap view and an original new layout called ellimap. The system has been implemented on a real case in the domain of the support to innovation.

Visualizing cooperative activities with ellimaps: the case of Wikipedia

Cooperation has become a key word in the emerging Web 2.0 paradigm. The nature and motivations of the various behaviours related to this type of cooperative activities remain however incompletely understood. The information visualization tools can play a crucial role from this perspective to analyse the collected data. This paper presents a prototype allowing visualizing some data about the Wikipedia history with a technique called ellimaps. In this context the recent CGD algorithm is used in order to increase the scalability of the ellimaps approach.

Mat'Graph: transformation matricielle de graphe pour visualiser des échanges électroniques

Graph and matrices are two well-known solutions for representing network data. Each of them presents some advantages and drawbacks. The approach discussed in this paper consists in transforming a graph on the basis of a matrix-based organisation of the visualization space, in order to obtain a new trade-off between the two kinds of representation. This technique, called MatGraph, has been used to visualize the e-mail interactions between the members of a construction project.

Ellimaps, une technique basée sur la loi d'inclusion pour représenter des hiérarchies avec noeuds pondérés

The treemap approach and its various evolutions are well known techniques to visualize hierarchies. They are efficient to optimize the occupation of the display space and to visualize large datasets. However, compared to classic tree representations, they admit some limitations in terms of perception of the dataset structure. This paper describes a new technique called ellimap in which the rectangles are replaced by ellipses in a treemap-like algorithm. The resulting view makes very intuitive the perception of the dataset structure, which has been confirmed by a formal comparative test.

An ambient workplace for raising awareness of internet-based cooperation

This paper discusses a prototype desktop ambient display system known as the Ambient Workplace (AW) that is used to visualise some aspects of cooperation among a group of co-workers. The AW draws on the ambient technology paradigm by providing a visualisation that represents the interactions of the co-workers (either individuals or groups) in their peripheral attention zone. The paper discusses the development of a prototype system based on a series of indices and uses a maritime flags metaphor. The paper also presents some early results from a user study.

VisuThread: un module de visualisation de conversations électroniques

Electronic messaging has become one of the most widely used software in the enterprises. Increasingly its usage goes beyond the scope for which it was initially designed. For instance, the users consider it as a tool supporting the management of their tasks. The inappropriateness of current e-mail clients becomes more and more patent. Several research works have studied how to enhance its functionalities, especially in the domain of graphical representation of information. This paper decribes VisuThread, a conversation visualization module integrated in an electronic messaging client. The proposed graphical representation aims to allow a rapid apprehension of the current state of a conversation. It highlights the chronological succession of messages as well as the participants to the conversation. Moreover, additional useful functions are also integrated, such as filtering, zooming, or access to the message editor.

Open Data Integration

Since several years, even some decades, a major problem in computer sciences is directly linked with data integration. When it becomes necessary to process information coming from different data sources, several problems may appear turning the process of integration more difficult to be n naccomplished. Nowadays, more and more information is flowing and is provided into the Web - Data Integration became even more important. The emerging trend of Open Data (OD) is an active actor for this event. Integrating data coming from public entities can be a difficult process. Large n nquantities of datasets are made available. However, an important level of heterogeneity may also exist: Datasets can be on different formats, forms and shapes. If the fact of being possible to access this information can be an important asset, it also can be completely useless if it is not n npossible to interpret so it can be used. Information Visualization may be an important tool to help the OD integration process. This paper presents problems and barriers which can be encountered on the OD integration process. The paper also describes how Information Visualization can be used to facilitate the integration of OD and turn the procedure more effective, friendlier, and faster.