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Chris Raymaekers

Bio: Chris Raymaekers is an academic researcher from University of Hasselt. The author has contributed to research in topics: User interface & Adaptation (computer science). The author has an hindex of 10, co-authored 26 publications receiving 305 citations.

Papers
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Proceedings ArticleDOI
28 Oct 2008
TL;DR: The reality-based approach in the combination of user interface and paint software is a new step forward to bridge the gap between physical and digital painting, as is demonstrated by initial user tests.
Abstract: This paper presents a novel interface for a digital paint system: IntuPaint. A tangible interface for a digital paint easel, using an interactive surface and electronic brushes with a tuft of bristles, has been developed. The flexible brush bristles conduct light by means of total internal reflection inside the individual bristles. This enables to capture subtle paint nuances of the artist in a way that was not possible in previous technologies. This approach provides natural interaction and enables detailed tracking of specific brush strokes. Additional tangible and finger-based input techniques allow for specific paint operations or effects. IntuPaint also offers an extensive model-based paint simulation, rendering realistic paint results. The reality-based approach in the combination of user interface and paint software is a new step forward to bridge the gap between physical and digital painting, as is demonstrated by initial user tests.

68 citations

Proceedings ArticleDOI
23 Nov 2009
TL;DR: A new interactive canvas, accurately registering brush footprints and paint strokes in high precision has been developed, based on the real-time imaging of brushes and other painting instruments as well as thereal-time co-located rendering of the painting results.
Abstract: This paper presents FluidPaint, a novel digital paint system using real wet brushes. A new interactive canvas, accurately registering brush footprints and paint strokes in high precision has been developed. It is based on the real-time imaging of brushes and other painting instruments as well as the real-time co-located rendering of the painting results. This new painting user interface enhances the user experience and the artist's expressiveness. User tests demonstrate the intuitive nature of FluidPaint, naturally integrating interface elements of traditional painting in a digital paint system.

55 citations

Proceedings ArticleDOI
23 Jun 2009
TL;DR: To investigate which types of robotic outcome measures are clinically relevant, appropriate movement tasks and tests for the haptic PHANTOM end-effector robot were designed in a virtual environment, while mainly significant correlations were found between specific functional measures and virtual movement tasks.
Abstract: Upper limb weakness due to Multiple Sclerosis has a major negative effect on the functional activities of the patient Promising developments in the field of rehabilitation robotics may enable additional exercise This study aims to investigate which types of robotic outcome measures are clinically relevant, in preparation of the evaluation for intervention studiesWithin this context, appropriate movement tasks and tests for the haptic PHANTOM end-effector robot were designed in a virtual environment These tasks focused on spatial accuracy, object manipulation and speed Outcome measures were: 1) virtual movement tests, recorded by the robot to quantify motor control; 2) clinical outcome measures such as the Motricity Index, Jamar and MicroFET hand-held dynamometer to evaluate muscle strength; and the Nine Hole Peg Test, Purdue Pegboard, ARAt and TEMPA to asses upper limb function and manual dexterity10 healthy controls performed the virtual movement tasks using the Phantom as interface 21 MS subjects with upper limb dysfunction caused by muscle weakness were included in an interventional training study Pearson correlations were calculated at baseline between the performance on the three virtual movement tasks and the clinical tests on impairment and activity level The virtual movement tests discriminated between healthy controls and MS patients with hand dysfunction In the MS patient group, no significant correlations were found between muscle strength tests and virtual movement tasks, while mainly significant correlations were found between specific functional measures (specifically ARAt and Purdue pegboard test) and virtual movement tasks

31 citations

Proceedings ArticleDOI
15 Nov 2007
TL;DR: A model-based user interface approach is introduced which introduces semantic information, represented using ontologies, during the modelling phase which makes it possible for the semantic information content to be chosen and adapted in complete freedom without considering the underlying framework.
Abstract: The integration of semantic information in virtual environment interaction is mostly still ad-hoc. The system is usually designed in such a way that the design of the framework incorporates the semantic information which then can be used to utilise these semantics during interaction. We introduce a model-based user interface approach which introduces semantic information, represented using ontologies, during the modelling phase. This semantic information itself is created during the design of the virtual world. The approach we propose is system independent and makes it possible for the semantic information content to be chosen and adapted in complete freedom without considering the underlying framework. We incorporate semantics in NiMMiT, our notation for multimodal interaction modelling. We present two case studies which validate the flexibility of our approach.

21 citations

Journal ArticleDOI
TL;DR: A conceptual framework for realizing adaptive personalized interaction in virtual environments is proposed and how to establish, verify and apply a user model is discussed, which forms the first and important step in implementing the proposed conceptual framework.
Abstract: When interacting in a virtual environment, users are confronted with a number of interaction techniques. These interaction techniques may complement each other, but in some circumstances can be used interchangeably. Because of this situation, it is difficult for the user to determine which interaction technique to use. Furthermore, the use of multimodal feedback, such as haptics and sound, has proven beneficial for some, but not all, users. This complicates the development of such a virtual environment, as designers are not sure about the implications of the addition of interaction techniques and multimodal feedback. A promising approach for solving this problem lies in the use of adaptation and personalization. By incorporating knowledge of a user's preferences and habits, the user interface should adapt to the current context of use. This could mean that only a subset of all possible interaction techniques is presented to the user. Alternatively, the interaction techniques themselves could be adapted, e.g. by changing the sensitivity or the nature of the feedback. In this paper, we propose a conceptual framework for realizing adaptive personalized interaction in virtual environments. We also discuss how to establish, verify and apply a user model, which forms the first and important step in implementing the proposed conceptual framework. This study results in general and individual user models, which are then verified to benefit users interacting in virtual environments. Furthermore, we conduct an investigation to examine how users react to a specific type of adaptation in virtual environments (i.e. switching between interaction techniques). When an adaptation is integrated in a virtual environment, users positively respond to this adaptation as their performance significantly improve and their level of frustration decrease.

18 citations


Cited by
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Journal ArticleDOI
Tamar Frankel1
TL;DR: The Essay concludes that practitioners theorize, and theorists practice, use these intellectual tools differently because the goals and orientations of theorists and practitioners, and the constraints under which they act, differ.
Abstract: Much has been written about theory and practice in the law, and the tension between practitioners and theorists. Judges do not cite theoretical articles often; they rarely "apply" theories to particular cases. These arguments are not revisited. Instead the Essay explores the working and interaction of theory and practice, practitioners and theorists. The Essay starts with a story about solving a legal issue using our intellectual tools - theory, practice, and their progenies: experience and "gut." Next the Essay elaborates on the nature of theory, practice, experience and "gut." The third part of the Essay discusses theories that are helpful to practitioners and those that are less helpful. The Essay concludes that practitioners theorize, and theorists practice. They use these intellectual tools differently because the goals and orientations of theorists and practitioners, and the constraints under which they act, differ. Theory, practice, experience and "gut" help us think, remember, decide and create. They complement each other like the two sides of the same coin: distinct but inseparable.

2,077 citations

Journal ArticleDOI
TL;DR: The recent progress of upper limb exoskeleton robots for rehabilitation treatment of patients with neuromuscular disorders and the fundamental challenges in developing these devices are described.

475 citations

Journal ArticleDOI
TL;DR: The state-of-the-art in 3D object selection techniques is surveyed, important findings in human control models are reviewed, major factors influencing selection performance are analyzed, and existing techniques are classified according to a number of criteria.

398 citations

Journal ArticleDOI
TL;DR: The results of present pilot study suggest that upper limb functionality of high-level disability MS patients can be positively influenced by means of a technology-enhanced physical rehabilitation program.
Abstract: Few research in multiple sclerosis (MS) has focused on physical rehabilitation of upper limb dysfunction, though the latter strongly influences independent performance of activities of daily living. Upper limb rehabilitation technology could hold promise for complementing traditional MS therapy. Consequently, this pilot study aimed to examine the feasibility of an 8-week mechanical-assisted training program for improving upper limb muscle strength and functional capacity in MS patients with evident paresis. A case series was applied, with provision of a training program (3×/week, 30 minutes/session), supplementary on the customary maintaining care, by employing a gravity-supporting exoskeleton apparatus (Armeo Spring). Ten high-level disability MS patients (Expanded Disability Status Scale 7.0-8.5) actively performed task-oriented movements in a virtual real-life-like learning environment with the affected upper limb. Tests were administered before and after training, and at 2-month follow-up. Muscle strength was determined through the Motricity Index and Jamar hand-held dynamometer. Functional capacity was assessed using the TEMPA, Action Research Arm Test (ARAT) and 9-Hole Peg Test (9HPT). Muscle strength did not change significantly. Significant gains were particularly found in functional capacity tests. After training completion, TEMPA scores improved (p = 0.02), while a trend towards significance was found for the 9HPT (p = 0.05). At follow-up, the TEMPA as well as ARAT showed greater improvement relative to baseline than after the 8-week intervention period (p = 0.01, p = 0.02 respectively). The results of present pilot study suggest that upper limb functionality of high-level disability MS patients can be positively influenced by means of a technology-enhanced physical rehabilitation program.

174 citations

Journal ArticleDOI
TL;DR: An authoring framework that aims to provide structured support, from content design to final implementation, of the SandBox Serious Game, a conceptual model which relies on a generalization of task-based learning theory, and proposes a top-down methodology for content preparation.
Abstract: Serious games present a promising opportunity for learning, but the genre still lacks methodologies and tools for efficient and low-cost production, particularly for teacher and domain experts This article gives an authoring framework that aims to provide structured support, from content design to final implementation In particular, we have abstracted a conceptual model—the SandBox Serious Game - which relies on a generalization of task-based learning theory The model invites players to perform cognitive tasks contextually while exploring information-rich virtual environments We consider it particularly suited for cultural heritage entertainment applications The model defines games that are set in realistic virtual worlds enriched with embedded educational tasks, which we have implemented as minigames This approach simplifies the authoring work, which can easily be supported by visual authoring tools for ontology-based urban 3D modeling and implementation tasks, thus allowing an approach similar to the mind-maps concept We propose a top-down methodology for content preparation, starting from a city-level analysis down to the single points of interest and associated tasks, which are instances of simple predefined minigame/quiz typologies We provide examples and discuss criteria for selecting task typologies according to the authors' cognitive targets Finally, we discuss the results of a user test, which took place in a lab, aimed at verifying the acquisition of cultural heritage knowledge in a pleasant and engaging way Games appear particularly suited for supporting the study of images, especially of iconography Compared to reading text, a game forces the player to focus more strongly on problems, which favors knowledge acquisition and retention Learning complex concepts requires an investigative attitude, which can be spurred by well-designed games Good design involves usability, graphic appeal, appropriate content, and the presence of connections which a player must discover in the content Players should be asked to pay attention to and reason about their whole game activity - including the relationships between the game content, the brief introduction, and concluding texts More comprehensive tests are needed to better investigate the educational effectiveness—however, the first results are promising, especially in terms of user motivation and creation of new opportunities for learning about CH

144 citations