This paper addresses culturally rooted factors within user interface design. The design implications of globalisation are discussed, together with the related processes of internationalisation, localisation, ‘glocalisation’, iconisation and culturalisation, in order to establish a basis for a new approach to HCI design. The potential for a more diverse culture-centred, design-based system—‘Culture-Centred Design’ (CCD) is introduced, and a CCD process developed.\ud \ud A redesigned computer interface, incorporating a consistent and culturally rooted metaphor for a Chinese user target group is discussed. A culturally specific ‘garden’ metaphor is developed and applied as an alternative to the current global ‘office’ or ‘desktop’ metaphor. A working demonstration of the interface is piloted with a group of Chinese users to assess its success in terms of interactivity, usability and cultural significance. The overall results of the first two evaluation phases have shown very positive outcomes for the use of the CCD system and Chinese garden metaphor

This paper describes the results of a survey which investigated and evaluated the needs and abilities of electric wheelchair users. The results of this survey will be used to develop a low-cost electric wheelchair-mounted robotic arm for use by physically disabled people to facilitate rehabilitation. The survey was undertaken by the author together with staff and students from occupational therapist training colleges, using a four-page questionnaire containing over 110 questions. The questionnaire was developed by the author together with Dr Robin Platts (Director of Orthotics), Mr Ian Bayley (Director of the London Spinal Unit) and senior occupational therapists at the Royal National Orthopaedic Hospital, Stanmore, Middlesex. After a successful trial the questionnaire was used with 50 severely disabled people from various backgrounds and social circumstances. The results of this survey show that the average electric wheelchair user is 40 years old, single (68%), living at home (58%) with family support (69%) and without any paid employment (79%). The most prevalent disability is spinal cord injury (24%) followed by multiple sclerosis (16%). The survey has identified several tasks which electric wheelchair users find impossible to do, and some of these will form part of the design specification. Finally 84% of the survey subjects would consider buying such a robotic aid.

The majority of research into full-sized helicopter overlapping propulsion systems involves co-axial setups (fully overlapped). Partially overlapping rotor setups (tandem, multirotor) have received less attention, and empirical data produced over the years is limited. The increase in demand for compact small unmanned aircraft has exposed the need for empirical investigations of overlapping propulsion systems at a small scale (Reynolds Number < 250,000). Rotor-to-rotor interference at the static state in various overlapping propulsion system configurations was empirically measured using off the shelf T-Motor 16 inch × 5.4 inch rotors. A purpose-built test rig was manufactured allowing various overlapping rotor configurations to be tested. First, single rotor data was gathered, then performance measurements were taken at different thrust and tip speeds on a range of overlap configurations. The studies were conducted in a system torque balance mode. Overlapping rotor performance was compared to an isolated dual rotor propulsion system revealing interference factors which were compared to the momentum theory. Tests revealed that in the co-axial torque-balanced propulsion system the upper rotor outperforms the lower rotor at axial separation ratios between 0.05 and 0.85. Additionally, in the same region, thrust sharing between the two rotors changed by 21%; the upper rotor produced more thrust than the lower rotor at all times. Peak performance was recorded as a 22% efficiency loss when the axial separation ratio was greater than 0.25. The performance of a co-axial torque-balanced system reached a 27% efficiency loss when the axial separation ratio was equal to 0.05. The co-axial system swirl recovery effect was recorded to have a 4% efficiency gain in the axial separation ratio region between 0.05 and 0.85. The smallest efficiency loss (3%) was recorded when the rotor separation ratio was between 0.95 and 1 (axial separation ratio was kept at 0.05). Tests conducted at a rotor separation ratio of 0.85 showed that the efficiency loss decreased when the axial separation ratio was greater than 0.25. The lower rotor outperformed the upper rotor in the rotor separation ratio region from 0.95 to 1 (axial separation ratio was kept at 0.05) at an overall system thrust of 8 N, and matched the upper rotor performance at the tested overall thrust of 15 N.

Co-axial propeller systems have been used successfully in fixed-wing aircraft for many years due to their inherently good performance. Likewise, several pioneering rotary-winged aircraft projects used co-axial rotors, such as the Westland WG-25 Mote, Gyrodyne DASH, and a range of rotorcraft from Kamov in Russia. There has been much debate over the years about whether the co-axial rotor arrangement is more efficient than traditional layouts. Our findings point to the fact that although the co-axial arrangement has a reduced power output of up to 15% when compared to an equivalent single rotor system, this can be offset by the elimination of the need for a tail rotor, which could save up to 20% of the required power. It is only recently that this type of technology has reached the small UAV market in the form of a series of semi-autonomous and autonomous rotorcraft which are starting to make their mark in the military, homeland security and civilian fields. This paper investigates the use of such systems and discusses their advantages, disadvantages and performance metrics.