Thorsten Hampel

A peer-to-peer architecture for massive multiplayer online games

Massive Multiplayer Online Games with their virtual gaming worlds grow in user numbers as well as in the size of the virtual worlds. With this growth comes a significant increase of the requirements for server hardware. Today an MMOG provider usually faces the problem of serving thousands of users with entire server clusters. Peer-to-Peer networks with their high scalability and flexibility meet the requirements of connecting hundreds of thousands of people all over the world without a central server. In doing so the network bandwidth requirements remain at a reasonable level. In this work we propose to combine MMOGs with a Peer-to-Peer network. We introduce a game architecture capable of exploiting the flexibility and scalability of P2P networks. A P2P architecture based on an overlay network using distributed hash tables with support for persistent object storage and event distribution has been developed to meet MMOG requirements.

sTeam: structuring information in team-distributed knowledge management in cooperative learning environments

Learning is a socially embedded design process. But most of todays hypermedia systems fail to properly support the design-related and the social aspects of learning. Authoring and Web-publishing systems aim to support the authors design processes. Consequently, the activities of learners are confined to selecting and reading. Based on some fundamental reflections on the role of technology in learning processes, we conclude that top priority must be given to the construction of infrastructures that support cooperative learning processes if we are to properly harness the technologys potential. We present a learner-centered, wholly Web-based approach for structuring information in teams (sTeam). In sTeam the key concept is virtual space. It draws cooperation and communication together, while at the same time embodying the common external memory of a (virtual) learning group. Hence, the focus is not on interactive systems for individual access of knowledge bases, but on the cooperative management and structuring of distributed knowledge bases.

sTeam - Designing an integrative infrastructure for Web-based computer-supported cooperative learning

Learning is a socially embedded design process. But most of today’s hypermedia systems fail to properly support both the design-related and the social aspects of learning. Authoring and web-publishing systems aim to support the authors’ design process. Consequently, learners’ activities are confined to selecting and reading. Based on some fundamental reflections on the role of technology in learning processes, we conclude that top priority must be given to the construction of infrastructures that support cooperative learning processes if we are to properly harness technology’s potential. We present a learner-centered – wholly web-based – approach for structuring information in teams (sTeam). The key concept in sTeam is virtual space. It draws together cooperation and communication, at the same time embodying the common external memory of a (virtual) learning group. The focus is not, then, on interactive systems for individual accessing of knowledge bases, but rather on the cooperative management and structuring of distributed knowledge bases.

Deployment of simple user-centered collaborative technologies in educational institutions - experiences and requirements

In our modern society with its variety of learning and work processes, collaborative structuring of knowledge plays an important role. With new and growing phenomena in mind, such as the user-centered wiki systems, this paper looks at the various ways of organizing collaboration in virtual knowledge spaces. As part of a novel teaching concept - embedded in a system for cooperative knowledge organization - spatial structuring of knowledge forms an essential part of teaching and learning. Based on the evaluation results of this concept, the paper focuses on collaborative writing methods and the requirements of tools used with special consideration of wikis. It then goes on to describe the concrete realization of a fusion of semantic-spatial structuring techniques and collaborative writing considering as example the integration of wiki techniques into virtual knowledge spaces.

GATiB-CSCW, Medical Research Supported by a Service-Oriented Collaborative System

Medical research is a collaborative process in an interdisciplinary environment that may be effectively supported by a Computer Supported Cooperative Work (CSCW) system. Such a system imposes specific requirements in order to allow flexible integration of data, analysis services and communication mechanisms. Persons with different expertise and access rights cooperate in mutually influencing contexts (e.g. clinical studies, research cooperations). Thus, appropriate virtual environments are needed to facilitate context-aware communication, deployment of biomedical tools as well as data and knowledge sharing. We systematically elaborate the main requirements of a medical CSCW system and present a conceptual model, as well as an architectural proposal satisfying the demands. We design a prototypical virtual workbench to support research and routine activities in the context of the GATiB (Genome Austria Tissue Bank) initiative.

Pragmatic solutions for better integration of the visually impaired in virtual communities

This article introduces and discusses issues in the design of user interfaces for visually impaired people in the domain of virtual communities. We begin by pointing out that collaborative virtual environments provide additional means for visually impaired people which may help to accomplish a better integration into existing communities and social activities. We give a short introduction to the way visually impaired people usually work with a PC and show how their method of information access differs to sighted people. We then take a look at the advantages and disadvantages of existing adaptations to operating systems. Based on this analysis we describe some requirements for user interfaces the usability for visually impaired people without losing the attractiveness and intuitiveness for the sighted. We finally describe a prototype of a special IRC-Client, called BIRC, and discuss its advantages and limitations.

Re-conceptualizing learning environments: a framework for pervasive elearning

Pervasive e-learning requires a novel media perspective on learning objects. Instead of viewing handhelds or smart phones as minimized PCs we would like to propose a perspective on the notion of learning objects as active semiotics. We illustrate the use of such learning objects in distributed knowledge spaces which are a key concept for building up pervasive learning environments. We sketch a framework for implementing knowledge spaces and show how we use this framework for setting up learning environments. Finally, we discuss how we intend to extend this framework to cope with distributed knowledge spaces as part of distributed server environments as well as mobile ad hoc networks. We regard this extension as a key to build up real pervasive learning environments that transcend todays e-learning frameworks.

Wasabi Beans - SOA for collaborative learning and working systems

The recent developments in the scope of Web 2.0 highlight the benefits of exchanging userspsila experiences and turn the focus onto collaborative working. E-learning ecosystems and CSCW systems should aim to provide as many functionalities as needed from users in order to act as a centralized interface for their collaborative learning and daily work. Since more and more functionalities are made available as Web services, these can be adapted into a collaborative system. In contemporary collaborative systems, however, such an adaption is often a challenge. Service oriented architectures (SOAs) facilitate the adaption and linking of Web services and build an ideal platform for new e-learning ecosystems and CSCW systems. This paper presents the key aspects of turning the established CSCW system open-sTeam into a service oriented architecture (SOA). Our new flexible Wasabi framework, based on EJB 3 and JBoss, results in the next level of e-learning ecosystems and CSCW enterprise architectures which is highly adaptable due to the support of Web services.

Collaboration by illustration: real-time visualization in Web3D

Graphical representation of complex data sets is an important method for supporting scientific collaboration. Following this idea, we developed a novel Web3D-based visualization framework that supports synchronous as well as asynchronous cooperation, even of spatially separated scientist. Our open Visaar framework open-source technology and combines innovative techniques from the area of computer-generated visualization with modern achievements of CSCW (Computer Supported Cooperative Work). Therefore, we extended OpenSG with the functionality for supporting cooperative and remote features. OpenSG is a portable scene graph system to create real-time graphics applications. openVisaar is designed to accompany state-of-the-art CSCW systems in the collaboration process by embedding the visualization features into the co-operation environment. For this purpose openVisaar provides a rich set of interfaces. By combining both worlds -- visualization and CSCW - users of our system get an up-to-date all-in-one solution for collaborating with real world data.

A design pattern for mobile-distributed knowledge spaces

Mobility in collaboration is one of the key challenges for CSCW/L research. This contribution first looks at the central dimensions of connectivity, context and consistency for mobile collaboration out of a media viewpoint and a technical viewpoint. As a second step our architecture for mobile knowledge spaces is presented alongside these dimensions.