Combining monoSLAM with object recognition for scene augmentation using a wearable camera

In wearable visual computing, maintaining a time-evolving representation of the 3D environment along with the pose of the camera provides the geometrical foundation on which person-centred processing can be built. In this paper, an established method for the recognition of feature clusters is used on live imagery to identify and locate planar objects around the wearer. Objects’ locations are incorporated as additional 3D measurements into a monocular simultaneous localization and mapping process, which routinely uses 2D image measurements to acquire and maintain a map of the surroundings, irrespective of whether objects are present or not. Augmenting the 3D maps with automatically recognized objects enables useful annotations of the surroundings to be presented to the wearer. After demonstrating the geometrical integrity of the method, experiments show its use in two augmented reality applications.     

Exploring MARS: developing indoor and outdoor user interfaces to a mobile augmented reality system

We describe an experimental mobile augmented reality system (MARS) testbed that employs different user interfaces to allow outdoor and indoor users to access and manage information that is spatially registered with the real world. Outdoor users can experience spatialized multimedia presentations that are presented on a head-tracked, see-through, head-worn display used in conjunction with a hand-held pen-based computer. Indoor users can get an overview of the outdoor scene and communicate with outdoor users through a desktop user interface or a head- and hand-tracked immersive augmented reality user interface.     

Human factors and qualitative pedagogical evaluation of a mobile augmented reality system for science education used by learners with physical disabilities

Technology-enhanced learning, employing novel forms of content representation and education service delivery by enhancing the visual perception of the real environment of the user, is favoured by proponents of educational inclusion for learners with physical disabilities. Such an augmented reality computer-mediated learning system has been developed as part of an EU funded research project, namely the CONNECT project. The CONNECT project brings together schools and science centres, and produces novel information and communication technologies based on augmented reality (AR) and web-based streaming and communication, in order to support learning in a variety of settings. The CONNECT AR interactive learning environment can assist users to better contextualize and reinforce their learning in school and in other settings where people learn (i.e. science centres and home). The CONNECT concept and associated technologies encourage users to visit science centres and perform experiments that are not possible in school. They can also build on these experiences back at school and at home with visual augmentations that they are communicated through web-based streaming technology. This paper particularly focuses on a user-centred evaluation approach of human factors and pedagogical aspects of the CONNECT system, as applied to a special needs user group. The main focus of the paper is on highlighting the human factors issues and challenges, in terms of wearability and technology acceptance, while elaborating on some qualitative aspects of the pedagogical effectiveness of the instructional medium that AR technology offers for this group of learners.

The development of a panorama manifestation virtual reality system for navigation and a usability comparison with a desktop system

The virtual reality (VR) system has become popular in the last two decades and is being applied increasingly to navigation studies. This study developed a panorama manifestation (PM) VR system, with six monitors forming a circular display and an interactive chair equipped with rotation sensors and operating knobs. The advantages of the PM system include a large circular display, a body-centred design, body engagement and a low set-up cost. Based on navigation experimental tasks, this system's usability was compared with that of a typical desktop (DT) system. The results showed that participants using the PM system had a significantly higher success rate and required less completion time than participants using the DT system, indicating that the PM system outperforms the DT system in terms of effectiveness and efficiency in some navigation tasks, and also suggesting that the PM system may require lower spatial cognition workload in the navigation tasks. However, the participants’ subjective evaluations of task difficulty (TD) failed to reach significance although the PM group did report a lower mean value for TD. Additionally, in the PM system, the participants’ spatial ability was more predictive to their navigation performance than that in the DT system, indicating that the PM system offered greater usability for some spatial experiments and could provide more support for participants’ navigation tasks.     

A novel mixed reality assistive system to aid the visually and mobility impaired using a multimodal feedback system

Most of the people affected by vision impairments are over 50 years old, which amplifies cognitive impairments and the risk of falling. This paper proposes a mixed reality assistive system to aid the navigation of visually impaired people by using a Smart Walker, audio feedback to provide cues to be followed, and vibratory feedback to indicate obstacles. To validate this system, 24 volunteers participated of three tasks consisting in a combination of a control strategy (Free Roam, Steering-Assisted Navigation, and Virtual Trail) and a path. To evaluate the experiments, task performance metrics and three questionnaires (Quality of Experience, SUS, and NASA-TLX) were assessed. According to SUS, all control strategies scored above 70, indicating their acceptability. Analyzing and comparing the questionnaires results and the strategies used, the Steering-Assisted Navigation, in which the volunteers had to follow a path indicated only by the haptic feedback provided by the controller, was the most physically and mentally demanding. The other two strategies required less effort, physical, and mental demand. Despite requiring different cognitive loads for navigation, all control strategies combined with the multimodal sensory feedback guided the volunteers during the tasks, evidencing the feasibility of the system.     

Enhancement of digital reading performance by using a novel web-based collaborative reading annotation system with two quality annotation filtering mechanisms

Collaboratively annotating digital texts allows learners to add valued information, share ideas, and create knowledge. However, excessive annotations and poor-quality annotations in a digital text may cause information overload and divert attention from the main content. The increased cognitive load ultimately reduces the effectiveness of collaborative annotations in promoting reading comprehension. Thus, this work develops a web-based collaborative reading annotation system (WCRAS-TQAFM) with two quality annotation filtering mechanisms—high-grade and master annotation filters—to promote the reading performance of learners. Ninety-seven students from three classes of a senior high school in Taiwan were invited to participate in an 80-min reading activity in which individual readers use WCRAS with or without annotation filters. Analytical results indicate that digital reading performance is significantly better in readers who use the high-grade annotation filter compared to those who read all annotations. Moreover, the high-grade annotation filter can enhance the reading comprehension of learners in all considered question types (i.e., recall, main idea, inference, and application). Also, the Cohen’s kappa statistics was used for assessing whether the annotation selected by the high-grade annotation filter is in agreement with the annotations selected by a domain expert. The statistic results indicate that the proposed high-grade annotation filter is valid to some degree. Finally, neither of the proposed quality annotation filtering approaches significantly reduces cognitive load.     

Networked multiplayer cooperative interaction using decoupled motion control method in a shared virtual environment with haptic,visual and movement feedback

This paper focuses on multiplayer cooperative interaction in a shared haptic environment based on a local area network. Decoupled motion control, which allows one user to manipulate a haptic interface to control only one‐dimensional movement of an avatar, is presented as a new type haptic‐based cooperation among multiple users. Users respectively move an avatar along one coordinate axis so that the motion of the avatar is the synthesis of movements along all axes. It is different from previous haptic cooperation where all users can apply forces on an avatar along any direction to move it, the motion of which completely depends on the resultant force. A novel concept of movement feedback is put forward where one user can sense other users’ hand motions through his or her own haptic interface. The concept can also be explained wherein one person who is required to move a virtual object along only one axis can also feel the motions of the virtual object along other axes. Movement feedback, which is a feeling of motion, differs from force feedback, such as gravity, collision force and resistance. A spring‐damper force model is proposed for the computation of motion feedback to implement movement transmission among users through haptic devices. Experimental results validate that movement feedback is beneficial for performance enhancement of such kind of haptic‐based cooperation, and the effect of movement feedback in performance improvement is also evaluated by all subjects.Copyright © 2012 John Wiley & Sons, Ltd.     

A novel structural modeling and analysis of VLSI interconnect with an RLC tree network system using a BG/SEBD approach

A practical and effective novel graphical structural modeling and analysis approach is presented.This approach is used for solving the state interactions modeling problem caused by the model approximations in VLSI interconnect for RLC tree network systems.The bond graph (BG) energy model with a simulink energy-based block diagram (SEBD) algorithm is developed.The dynamic behaviors of an example of VLSI interconnect with a 20th-order RLC tree are presented.Methods of sequent structuring and the delineation o...     

A new multi-stable fractional-order four-dimensional system with self-excited and hidden chaotic attractors: Dynamic analysis and adaptive synchronization using a novel fuzzy adaptive sliding mode control method

Four-dimensional chaotic systems are a very interesting topic for researchers, given their special features. This paper presents a novel fractional-order four-dimensional chaotic system with self-excited and hidden attractors, which includes only one constant term. The proposed system presents the phenomenon of multi-stability, which means that two or more different dynamics are generated from different initial conditions. It is one of few published works in the last five years belonging to the aforementioned category. Using Lyapunov exponents, the chaotic behavior of the dynamical system is characterized, and the sensitivity of the system to initial conditions is determined. Also, systematic studies of the hidden chaotic behavior in the proposed system are performed using phase portraits and bifurcation transition diagrams. Moreover, a design technique of a new fuzzy adaptive sliding mode control (FASMC) for synchronization of the fractional-order systems has been offered. This control technique combines an adaptive regulation scheme and a fuzzy logic controller with conventional sliding mode control for the synchronization of fractional-order systems. Applying Lyapunov stability theorem, the proposed control technique ensures that the master and slave chaotic systems are synchronized in the presence of dynamic uncertainties and external disturbances. The proposed control technique not only provides high performance in the presence of the dynamic uncertainties and external disturbances, but also avoids the phenomenon of chattering. Simulation results have been presented to illustrate the effectiveness of the presented control scheme.