Due to the need for large numbers of layers and size limitations, current layered manufacturing technologies are not suitable for the fabrication of large sized free-form objects. For this purpose a novel technology of thick layered object manufacturing is being developed, based on higher order approximation of the initial geometry, and the application of a flexible curved cutting tool. The method allows us to produce physical prototypes with less or without any finishing. The technology of cutting foams by means of a heated flexible blade in polystyrene foam offers new possibilities. However to achieve the optimum output, optimization of the process parameters is needed. In this paper a closer look is taken into the process characteristics and the influential factors which are decisive for productive cutting. The authors summarize the results of the executed experimental tests. In these experiments the values of the most influential parameters were systematically changed and the effects were carefully investigated. The first results indicate that the cutting technology is practically feasible, but further research is needed in order to achieve a balanced optimization of the technology from all aspects.

A novel technology introduced by the authors as free form thick layered object manufacturing (FF-TLOM), aims specifically at the field of large sized free form objects. The system under development will be able to produce large editable free form prototypes that can be used in the conceptual phase of the design. The considered technology of cutting polystyrene slabs using a heated flexible cutting blade is developed and currently being optimized. Work has been done already on the control of the actual cutting process by elaborating experiments on a range of influential process parameters. A further step is the accurate control of the shape of the flexible cutting device. Theories are known for the calculation of the shape of a flexible bar under specific constraints. The known theories and algorithms must be validated by experimental verification. The paper describes explorative experiments with the aim to develop a method that can be used for this experimental verification. Two implemented algorithms for the calculation of blade shapes are described as well as a number of calculations that were performed using these algorithms. The calculated results are being compared to each other and to real world experiments in order to determine their validity. The results of the experiments indicate that both of the algorithms could be applied for our shape calculations, however more experiments and analysis have to be performed on the subject. It becomes clear that small deviations in the applied constraints can, under specific circumstances, have large effects on the generated blade shapes.

Brain signal and eye tracking technology have been intensively applied in cognitive science in order to study reading, listening and learning processes. Though promising results have been found in laboratory experiments, there are no smart reading aids that are capable to estimate difficulty during normal reading. This paper presents a new concept that aims to tackle this challenge. Based on a literature study and an experiment, we have identified several indicators for characterizing word processing difficulty by interpreting electroencelography (EEG) and electrooculography (EOG) signals. We have defined a computational model based on fuzzy set theory, which estimates the probability of word processing and comprehension difficulty during normal reading. The paper also presents a concept and functional prototype of a smart reading aid, which is used to demonstrate the feasibility of our solution. The results of our research proves that it is possible to implement a smart reading aid that is capable to detect reading difficulty in real time. We show that the most reliable indicators are related to eye movement (i.e. fixation and regression), while brain signals are less dependable sources for indicating word processing difficulty during continuous reading.

The paradigm of tangible virtuality (TV) has grown out from the paradigm of virtual reality (VR), leaving some key concepts of projective and immersive VR behind, but introducing many new ones. The ultimate objective of TV is to intuitively generate air-borne synthetic objects (SOs), share them between remote work environments in real time, simulate their physical behavior, and enable a physics-obeying interaction of humans with SOs. The major challenges for the implementation of TV originate in the need for multi-sensory integral rendering of SOs and un-instrumented generation of high fidelity sensations. These scientific and technological challenges have a strong influence on the current advancement of TV. Actually, implementation of fully featured TV environments is still in its infancy. The goal of this paper is to analyze the main implementation concepts and to make an inventory of the technological challenges and opportunities. Six major issues have been identified: (i) use of natural interaction modalities to express SOs, (ii) multi-aspect (e.g., tactile, haptic and auditory) volumetric rendering and sensation of air-borne SOs, (iii) simulation of physical behavior of interacting SOs, and (iv) manipulative human interaction with SOs. The paper investigates the opportunities of a short-term implementation based on the current technologies and of a near-future implementation based on emerging and anticipated technologies. The conclusion is that current technologies allow only a limited implementation of SOs and a low fidelity multi-sensorial experience. For a full scale implementation, radically new technologies and implementation concepts are needed, but it also requires a goal-driven extension of the existing scientific knowledge.

The goal of this paper is to explore the field of haptic feedback technologies from the aspect of airborne visualization applications. While conventional Virtual Reality (VR) applications in most cases make extensive use of body mounted equipment this is expected to be unfavorable for airborne visualization environments. There new constraints and demands will govern. We give an overview of currently known VR technologies and explore possible directions in which new solutions for airborne visualization environments should be searched.

The goal of this paper is to explore the field of haptic feedback technologies, and give an overview on which principles are currently available for communicating different properties of virtual artifacts in a haptic/tactile manner to users. Secondly we evaluate this information from the aspect of a new virtual interaction environment that is being implemented in our research group, which aims at airborne representation of virtual objects without the need of body connected equipment, like for example goggles or exoskeletons. Based on this evaluation we try to discriminate which principles could be applied in order to create a realistic haptic feedback in this virtual interaction environment.

An evergreen topic of human-computer interaction research is multi-modality. It has been considered important for the user interface of future computer aided conceptual design systems and what is hoped is that integration of, for instance, voice control, hand gesture/motion processing, and physical object scanning can increase both the semantic level and the efficiency of the interaction. In the area of computer mediated shape conceptualization, especially human hand motion detection and processing can play an important role. The authors’ research focuses on the study of the opportunities offered by hand motion processing in shape conceptualization. As a first step they have studied the state of the art and analyzed the technologies applicable to hand motion processing. This paper reports on the findings. The various technologies have been sorted in four categories: direct incomplete, direct complete, indirect incomplete and indirect complete detection. First, the principles supporting this categorization are explained in Section 2. The next four sections of the paper investigate the hand motion detection and processing technologies. Section 7 discusses the characteristics and operational parameters from the aspect of using hand motion for shape input in conceptual design. Our conclusion is that the currently known technologies do not absolutely support processing of a language of hand motions that is under development for creative shape conceptualization. Therefore, the hand motion language needs to be redesigned and adapted to the best technology.