Exploring mixed reality in distributed collaborative learning environments

Society is moving rapidly towards a world, where technology enables people to exist in a blend of physical and virtual realities. In education, this vision involves technologies ranging from smart classrooms to e-learning, creating greater opportunities for distance learners, bringing the potential to change the fundamental nature of universities. However, to date, most online educational platforms have focused on conveying information rather than supporting collaborative physical activities which are common in university science and engineering laboratories. Moreover, even when online laboratory support is considered, such systems tend to be confined to the use of simulations or pre-recorded videos. The lack of support for online collaborative physical laboratory activities, is a serious shortcoming for distance learners and a significant challenge to educators and researchers. In working towards a solution to this challenge, this thesis presents an innovative mixed-reality framework (computational model, conceptual architecture and proof-of-concept implementation) that enables geographically dispersed learners to perform co-creative teamwork using a computer-based prototype comprising hardware and software components. Contributions from this work include a novel distributed computational model for synchronising physical objects and their 3D virtual representations, expanding the dual-reality paradigm from single linked pairs to complex groupings, addressing the challenge of interconnecting geographically dispersed environments; and the creation of a computational paradigm that blends a model of distributed learning objects with a constructionist pedagogical model, to produce a solution for distributed mixed-reality laboratories. By way of evidence to support the research findings, this thesis reports on evaluations performed with students from eight different universities in six countries, namely China, Malaysia, Mexico, UAE, USA and UK; providing an important insight to the role of social interactions in distance learning, and demonstrating that the inclusion of a physical component made a positive difference to students’ learning experience, supporting the use of cross-reality objects in educational activities

A Fuzzy Logic based system for Mixed Reality assistance of remote workforce

The recent years have witnessed an increase in the use of augmented and virtual reality systems, changing the way we interact with our environments. Such systems are commonly associated with advertising, entertainment, medicine, training and education. However, with the increasing acceptance and availability of mobile and wearable devices (e.g. head-mounted displays (HMD)), the use of these technologies is moving towards professional and industrial environments, where they would be able to support employees in their daily tasks, increasing customer satisfaction and reducing business costs. This paper presents an innovative Mixed Reality (MR) system to assist field workforce in remote locations. As part of the overall implementation, the MR system uses fuzzy logic mechanisms to improve accuracy in user tracking and object monitoring, allowing the correct representation of users and objects in the Graphical User Interfaces (GUIs), and improving the experience for users

Measurement driven quantum evolution

We study the problem of mapping an unknown mixed quantum state onto a known pure state without the use of unitary transformations. This is achieved with the help of sequential measurements of two non-commuting observables only. We show that the overall success probability is maximized in the case of measuring two observables whose eigenstates define mutually unbiased bases. We find that for this optimal case the success probability quickly converges to unity as the number of measurement processes increases and that it is almost independent of the initial state. In particular, we show that to guarantee a success probability close to one the number of consecutive measurements must be larger than the dimension of the Hilbert space. We connect these results to quantum copying, quantum deleting and entanglement generation.Comment: 7 pages, 1 figur

Validity of ultrasonography and measures of adult shoulder function and reliability of ultrasonography in detecting shoulder synovitis in patients with rheumatoid arthritis using magnetic resonance imaging as a gold standard

Objective. To assess the intra- and interobserver reproducibility of musculoskeletal ultrasonography (US) in detecting in.ammatory shoulder changes in patients with rheumatoid arthritis, and to determine the agreement between US and the Shoulder Pain and Disability Index (SPADI) and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, using magnetic resonance imaging (MRI) as a gold standard. Methods. Eleven rheumatologists investigated 10 patients in 2 rounds independently and blindly of each other by US. US results were compared with shoulder function tests and MRI. Results. The positive and negative predictive values (NPVs) for axillary recess synovitis (ARS) were 0.88 and 0.43, respectively, for posterior recess synovitis (PRS) were 0.36 and 0.97, respectively, for subacromial/subdeltoid bursitis (SASB) were 0.85 and 0.28, respectively, and the NPV for biceps tenosynovitis (BT) was 1.00. The intraobserver kappa was 0.62 for ARS, 0.59 for PRS, 0.51 for BT, and 0.70 for SASB. The intraobserver kappa for power Doppler US (PDUS) signal was 0.91 for PRS, 0.77 for ARS, 0.94 for SASB, and 0.53 for BT. The interobserver maximum kappa was 0.46 for BT, 0.95 for ARS, 0.52 for PRS, and 0.61 for SASB. The interobserver reliability of PDUS was 1.0 for PRS, 0.1 for ARS, 0.5 for BT, and 1.0 for SASB. P values for the SPADI and DASH versus cuff tear on US were 0.02 and 0.01, respectively; all other relationships were not significant. Conclusion. Overall agreements between gray-scale US and MRI regarding synovitis of the shoulder varied considerably, but excellent results were seen for PDUS. Measures of shoulder function have a poor relationship with US and MRI. Improved standardization of US scanning technique could further reliability of shoulder US. © 2010, American College of Rheumatology