@phdthesis{Mthunzi,
  author    = {Mthunzi, Everett},
  title     = {Interactive Surface Environments: Design and Implementation},
  doi       = {10.25643/bauhaus-universitaet.6406},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230704-64065},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  pages     = {128},
  abstract  = {This dissertation presents three studies on the design and implementation of interactive surface environments. It puts forward approaches to engineering interactive surface prototypes using prevailing methodologies and technologies. The scholarly findings from each study have been condensed into academic manuscripts, which are conferred herewith. The first study identifies a communication gap between engineers of interactive surface systems (i.e., originators of concepts) and future developers. To bridge the gap, it explores a UML-based framework to establish a formal syntax for modeling hardware, middleware, and software of interactive surface prototypes. The proposed framework targets models-as-end-products, towards enabling a shared view of research prototypes thereby facilitating dialogue between concept originators and future developers. The second study positions itself to support developers with an open-source solution for exploiting 3D point clouds for interactive tabletop applications using CPU architectures. Given dense 3D point-cloud representations of tabletop environments, the study aims toward mitigating high computational effort by segmenting candidate interaction regions as a preprocessing step. The study contributes a robust open-source solution for reducing computational costs when leveraging 3D point clouds for interactive tabletop applications. The solution itself is flexible and adaptable to variable interactive surface applications. The third study contributes an archetypal concept for integrating mobile devices as active components in augmented tabletop surfaces. With emphasis on transparent development trails, the study demonstrates the utility of the open-source tool developed in the second study. In addition to leveraging 3D point clouds for real-time interaction, the research considers recent advances in computer vision and wireless communication to realize a modern, interactive tabletop application. A robust strategy that combines spatial augmented reality, point-cloud-based depth perception, CNN-based object detection, and Bluetooth communication is put forward. In addition to seamless communication between adhoc mobile devices and interactive tabletop systems, the archetypal concept demonstrates the benefits of preprocessing point clouds by segmenting candidate interaction regions, as suggested in the second study. Collectively, the studies presented in this dissertation contribute; 1—bridging the gap between originators of interactive surface concepts and future developers, 2— promoting the exploration of 3D point clouds for interactive surface applications using CPU-based architectures, and 3—leveraging 3D point clouds together with emerging CNN-based object detection, and Bluetooth communication technologies to advance existing surface interaction concepts.},
  subject      = {Mensch-Maschiene-Kommunikation},
  language  = {en}
}
@phdthesis{Weissker,
  author    = {Weißker, Tim},
  title     = {Group Navigation in Multi-User Virtual Reality},
  doi       = {10.25643/bauhaus-universitaet.4530},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20211124-45305},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  pages     = {148},
  abstract  = {Multi-user virtual reality systems enable collocated as well as distributed users to perform collaborative activities in immersive virtual environments. A common activity in this context is to move from one location to the next as a group to explore the environment together. The simplest solution to realize these multi-user navigation processes is to provide each participant with a technique for individual navigation. However, this approach entails some potentially undesirable consequences such as the execution of a similar navigation sequence by each participant, a regular need for coordination within the group, and, related to this, the risk of losing each other during the navigation process. To overcome these issues, this thesis performs research on group navigation techniques that move group members together through a virtual environment. The presented work was guided by four overarching research questions that address the quality requirements for group navigation techniques, the differences between collocated and distributed settings, the scalability of group navigation, and the suitability of individual and group navigation for various scenarios. This thesis approaches these questions by introducing a general conceptual framework as well as the specification of central requirements for the design of group navigation techniques. The design, implementation, and evaluation of corresponding group navigation techniques demonstrate the applicability of the proposed framework. As a first step, this thesis presents ideas for the extension of the short-range teleportation metaphor, also termed jumping, for multiple users. It derives general quality requirements for the comprehensibility of the group jumping process and introduces a corresponding technique for two collocated users. The results of two user studies indicate that sickness symptoms are not affected by user roles during group jumping and confirm improved planning accuracy for the navigator, increased spatial awareness for the passenger, and reduced cognitive load for both user roles. Next, this thesis explores the design space of group navigation techniques in distributed virtual environments. It presents a conceptual framework to systematize the design decisions for group navigation techniques based on Tuckman's model of small-group development and introduces the idea of virtual formation adjustments as part of the navigation process. A quantitative user study demonstrates that the corresponding extension of Multi-Ray Jumping for distributed dyads leads to more efficient travel sequences and reduced workload. The results of a qualitative expert review confirm these findings and provide further insights regarding the complementarity of individual and group navigation in distributed virtual environments. Then, this thesis investigates the navigation of larger groups of distributed users in the context of guided museum tours and establishes three central requirements for (scalable) group navigation techniques. These should foster the awareness of ongoing navigation activities as well as facilitate the predictability of their consequences for all group members (Comprehensibility), assist the group with avoiding collisions in the virtual environment (Obstacle Avoidance), and support placing the group in a meaningful spatial formation for the joint observation and discussion of objects (View Optimization). The work suggests a new technique to address these requirements and reports on its evaluation in an initial usability study with groups of five to ten (partially simulated) users. The results indicate easy learnability for navigators and high comprehensibility for passengers. Moreover, they also provide valuable insights for the development of group navigation techniques for even larger groups. Finally, this thesis embeds the previous contributions in a comprehensive literature overview and emphasizes the need to study larger, more heterogeneous, and more diverse group compositions including the related social factors that affect group dynamics. In summary, the four major research contributions of this thesis are as follows: - the framing of group navigation as a specific instance of Tuckman's model of small-group development - the derivation of central requirements for effective group navigation techniques beyond common quality factors known from single-user navigation - the introduction of virtual formation adjustments during group navigation and their integration into concrete group navigation techniques - evidence that appropriate pre-travel information and virtual formation adjustments lead to more efficient travel sequences for groups and lower workloads for both navigators and passengers Overall, the research of this thesis confirms that group navigation techniques are a valuable addition to the portfolio of interaction techniques in multi-user virtual reality systems. The conceptual framework, the derived quality requirements, and the development of novel group navigation techniques provide effective guidance for application developers and inform future research in this area.},
  subject      = {Virtuelle Realit{\"a}t},
  language  = {en}
}
@phdthesis{Kunert,
  author    = {Kunert, Andr{\´e}},
  title     = {3D Interaction Techniques in Multi-User Virtual Reality : towards scalable templates and implementation patterns for cooperative interfaces},
  doi       = {10.25643/bauhaus-universitaet.4296},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20201204-42962},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  pages     = {147},
  abstract  = {Multi-user projection systems provide a coherent 3D interaction space for multiple co-located users that facilitates mutual awareness, full-body interaction, and the coordination of activities. The users perceive the shared scene from their respective viewpoints and can directly interact with the 3D content. This thesis reports on novel interaction patterns for collaborative 3D interaction for local and distributed user groups based on such multi-user projection environments. A particular focus of our developments lies in the provision of multiple independent interaction territories in our workspaces and their tight integration into collaborative workflows. The motivation for such multi-focus workspaces is grounded in research on social cooperation patterns, specifically in the requirement for supporting phases of loose and tight collaboration and the emergence of dedicated orking territories for private usage and public exchange. We realized independent interaction territories in the form of handheld virtual viewing windows and multiple co-located hardware displays in a joint workspace. They provide independent views of a shared virtual environment and serve as access points for the exploration and manipulation of the 3D content. Their tight integration into our workspace supports fluent transitions between individual work and joint user engagement. The different affordances of various displays in an exemplary workspace consisting of a large 3D wall, a 3D tabletop, and handheld virtual viewing windows, promote different usage scenarios, for instance for views from an egocentric perspective, miniature scene representations, close-up views, or storage and transfer areas. This work shows that this versatile workspace can make the cooperation of multiple people in joint tasks more effective, e.g. by parallelizing activities, distributing subtasks, and providing mutual support. In order to create, manage, and share virtual viewing windows, this thesis presents the interaction technique of Photoportals, a tangible interface based on the metaphor of digital photography. They serve as configurable viewing territories and enable the individual examination of scene details as well as the immediate sharing of the prepared views. Photoportals are specifically designed to complement other interface facets and provide extended functionality for scene navigation, object manipulation, and for the creation of temporal recordings of activities in the virtual scene. A further objective of this work is the realization of a coherent interaction space for direct 3D input across the independent interaction territories in multi-display setups. This requires the simultaneous consideration of user input in several potential interaction windows as well as configurable disambiguation schemes for the implicit selection of distinct interaction contexts. We generalized the required implementation structures into a high-level software pattern and demonstrated its versatility by means of various multi-context 3D interaction tools. Additionally, this work tackles specific problems related to group navigation in multiuser projection systems. Joint navigation of a collocated group of users can lead to unintentional collisions when passing narrow scene sections. In this context, we suggest various solutions that prevent individual collisions during group navigation and discuss their effect on the perceived integrity of the travel group and the 3D scene. For collaboration scenarios involving distributed user groups, we furthermore explored different configurations for joint and individual travel. Last but not least, this thesis provides detailed information and implementation templates for the realization of the proposed interaction techniques and collaborative workspaces in scenegraph-based VR systems. These contributions to the abstraction of specific interaction patterns, such as group navigation and multi-window interaction, facilitate their reuse in other virtual reality systems and their adaptation to further collaborative scenarios.},
  subject      = {Virtuelle Realit{\"a}t},
  language  = {en}
}
@phdthesis{Kaltenbrunner,
  author    = {Kaltenbrunner, Martin},
  title     = {An Abstraction Framework for Tangible Interactive Surfaces},
  doi       = {10.25643/bauhaus-universitaet.3717},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20180205-37178},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  pages     = {138},
  abstract  = {This cumulative dissertation discusses - by the example of four subsequent publications - the various layers of a tangible interaction framework, which has been developed in conjunction with an electronic musical instrument with a tabletop tangible user interface. Based on the experiences that have been collected during the design and implementation of that particular musical application, this research mainly concentrates on the definition of a general-purpose abstraction model for the encapsulation of physical interface components that are commonly employed in the context of an interactive surface environment. Along with a detailed description of the underlying abstraction model, this dissertation also describes an actual implementation in the form of a detailed protocol syntax, which constitutes the common element of a distributed architecture for the construction of surface-based tangible user interfaces. The initial implementation of the presented abstraction model within an actual application toolkit is comprised of the TUIO protocol and the related computer-vision based object and multi-touch tracking software reacTIVision, along with its principal application within the Reactable synthesizer. The dissertation concludes with an evaluation and extension of the initial TUIO model, by presenting TUIO2 - a next generation abstraction model designed for a more comprehensive range of tangible interaction platforms and related application scenarios.},
  subject      = {Informatik},
  language  = {en}
}
@phdthesis{Hogan,
  author    = {Hogan, Trevor},
  title     = {Data and Dasein - A Phenomenology of Human-Data Relations},
  doi       = {10.25643/bauhaus-universitaet.2905},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170323-29056},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  abstract  = {In contemporary society, data representation is an important and essential part of many aspects of our daily lives. This thesis aims to contribute to our understanding on how people experience data and what role representational modality plays in the process of perception and interpretation. This research is grounded in phenomenology - I align my theoretical exploration to ideas and concepts from philosophical phenomenology, while also respecting the essence of a phenomenological approach in the choice and application of methods. Alongside offering a rich description of people's experience of data representation, the key contributions I claim transcend four areas: theory, methods, design, and empirical findings. From a theoretical perspective, besides describing a phenomenology of human-data relations, I define, for the first time, multisensory data representation and establish a design space for the study of this class of representation. In relation to methodologies, I describe and deploy two methods to investigate different aspects of data experience. I blend the Repertory Grid technique with a focus group session and show how this adaption can be used to elicit rich design relevant insight. I also introduce the Elicitation Interview technique as a method for gathering detailed and precise accounts of human experience. Furthermore, I describe for the first time, how this technique can be used to elicit accounts of experience with data. My contribution to design relates to the creation of a series of bespoke data-driven artefacts, as well as describing an approach to design that I call Design Probes, which allows researchers to focus their enquiry on specific design features. To answer the research questions I set out in this thesis, I report on a series of empirical studies that used the aforementioned methods. The findings of these studies show, for instance, how certain representational modalities cause us to have heightened awareness of our body, some are more difficult to interpret than others, some rely heavily on instinct and each of them solicit us to reference external events during the process of interpretation. I conclude that a phenomenology of human-data relations show how representational modality affects the way we experience data, it also shows how this experience unfolds and it offers insight into particular moments such as the formation of meaning.},
  subject      = {Design},
  language  = {en}
}