Christoph Beckmann

Informing the design of group recommender systems

In this paper we present a literature study on social psychological concepts, which informs the design of group recommender process models in group recommender systems. We matched core concepts to well-established factors influencing satisfaction in groups, and obtained three most relevant social psychological concepts: group identification, group norms, and social roles.

AGReMo: providing ad-hoc groups with on-demand recommendations on mobile devices

Recommender systems provide users with suggestions of artefacts or other users. Group recommender systems facilitate decision making in groups of users who need to make a choice together. In this paper we introduce a novel approach providing ad-hoc groups of users who want to watch a movie together with shared on-demand recommendations on mobile devices. We present the AGReMo system and report on a user study.

The PPPSpace: Innovative Concepts for Permanent Capturing, Persistent Storing, and Parallel Processing and Distributing Events

Media spaces provide users with flexible support for easy interaction with technology and with each other, both at the same place and over distance. From a technological perspective the development of these environments is often inefficient, since most environments are developed specifically, without any synergies or reuse of previous concepts and implementations. In this paper we present the cooperative media space PPPSpace that is based on powerful technical parallel and distributed software engineering concepts and at the same time easy to use for end-users.

Towards a group recommender process model for ad-hoc groups and on-demand recommendations

Movie recommender systems simplify the movie selection by providing movie suggestions based on the respective users personal taste. Most of the current systems address individual users, support stationary use, and require pre-configuration. In this paper we present an approach for group recommendations for movies based on a novel group recommender process model for ad-hoc groups with on-demand recommendations.

GroupRecoPF: Innovative Group Recommendations in a Distributed Platform

Group recommender systems provide groups of users with shared recommendations. They have great potential for easing group decision processes, while at the same time entailing new technological and user-centred challenges. In this paper we present the GroupRecoPF platform providing developers with support for building scalable and user-friendly group recommender systems. It leverages on advanced concepts for group recommendation merging strategy exploration, performance optimisation, session persistence and mobility, as well as open interfaces.

MagnetiCode: physical mobile interaction through time-encoded magnetic identification tags

We present MagnetiCode, a new tagging mechanism that allows for physical mobile interaction. MagnetiCode tags can be captured and decoded by every compass-equipped mobile phone. They rely on a novel approach of transmitting binary IDs in form of a pulsed magnetic field. MagnetiCode therefore is able to substitute static tagging mechanisms like QR codes or RFID tags, in situations where visual tags are not appropriate or the expected number of users with NFC-enabled devices is poor. We confirm the general feasibility of our approach in a study.

Advanced Publish and Subscribe for Distributed Sensor-Based Infrastructures: The CoLocScribe Cooperative Media Space

Sensor-based infrastructures are important base technology for cooperative media spaces that support the natural interaction of users with their physical environment and with other users beyond the traditional keyboard and mouse. Sensor-based infrastructures basically capture data from sensors, store and process these data, and provide the data to clients. Several infrastructures have been developed; they all have their specific strengths in supporting either publish or subscribe, push or pull. In this paper we present a generic and advanced concept and implementation of a publish and subscribe mechanism for distributed sensor-based infrastructures that is sophisticated yet easy to configure and that is resource-saving through load balancing and provides push and pull. We exemplify this publish and subscribe mechanism in the CoLocScribe use case where we designed and developed advanced publish and subscribe for a cooperative media space.

Social Computing--Bridging the Gap between the Social and the Technical

Developing cooperative systems and social media requires taking complex decisions concerning the social interaction to be supported as well as the technical foundation. In this paper we build on the long and successful tradition of design patterns and the social framework of Erving Goffman. We present design patterns that address both challenges of social interaction and technical foundation--they provide input for software developers with respect to structuring software and to providing adequate support for the interaction of users with the environment and with each other.

RobustTrav: NAT Optimisation for the RobustCooperation Suite

Cooperative systems supporting remote teams are based on distributed software architectures. Underneath most of these architectures is the Internet Protocol version 4 (IPv4), which acts as technological backbone. Despite its strengths, the IPv4 also entails challenges for developers of such systems for getting system messages through firewalls without increasing latency and bringing delays for users. In this paper we introduce the Robust Cooperation Suite for communication, coordination, and collaboration, as well as its Robust Trav mechanism for effective and efficient NAT traversal.