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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The ergonomics and design of an inclusive best-fit solution to workbenches

Gaughran, William F. January 2004 (has links)
In a time when the developed world, is trying to reduce the human and economic costs of musculo-skeletal disorders (MSDs), any contribution to such an endeavour would be welcome. These economic costs are estimated to be in the tens of billions of Euro in the EU countries and similarly in the USA, the cost in human pain has not been measured. It may surprise many that in spite of all the advancements in science and technology, that two generations of people, who are very significantly taller than the people of a century ago, are still working in industry and in education at benches, which have not changed, either in height or design in centuries. Some, like wheelchair users do not have the opportunity to work at a bench at all. At the outset this research project, had the primary objective of determining an ergonomic best-fit, for a broad range of users of workbenches. These included the young school going population (12-13 year olds), the senior students (16 plus years old), adults, and a cohort of surrogate wheelchair users. The research also endeavoured to determine if adolescents, who were of the same stature as adults, had the same workbench ergonomics requirements. The secondary objective, which was completely dependant on the first, was to design a bench, which would suit the ergonomic requirements of this diverse group. The research has identified the best-fit workbench heights for the total cohort, while recognising the individual differences in relation to bench height ergonomics, for each of the sub-groups tested. The findings of the research have shown, that using surrogate wheelchair users to determine ergonomic data for this type of activity is fully justified. In combining the raw data for a similar number of wheelchair users, a best-fit bench height has been confirmed at 100 mm above knee height. There are no significant differences between the ergonomic requirements for males and females at workbenches. Body part discomfort has been reduced significantly, for the wheelchair users, at the identified height and endurance has been extended. Importantly the career options for wheelchair users have been extended, empowering them to make broader career choices. The outcomes of the research relating to three groups making up the able-bodied cohort have shown that an ergonomic best-fits possible, which suits the needs of this diverse group. A height of 150 mm under elbow height has been identified as best-fit, and this reduces the discomfort considerably while extending endurance. Robust working heights have been identified, but the female working heights at workbenches, are not as robust as for the males. For all groups it has been shown that bench height has a significant effect on body part discomfort and endurance, and while there were differences in efficiency, which were not quite significant, it is suggested that working in an ergonomically compromising position must, in the long term, in addition to increasing the risk of MSDs, likely also influence productivity, and quality of work. An inclusive test-workbench has been designed and built which satisfies the ergonomic needs of the diverse user group described above.
12

The development of ergonomics design criteria for powered human movement systems

Wilkins, Geoffrey J. M. January 2005 (has links)
This research developed from a concept for a powered exoskeletal system for manipulating a person's posture to provide them with physical sensations as though taking part in an activity in which they otherwise would not be able to participate. The aim for this research was to develop a set of criteria relating to this physical manipulation, which could be used, in conjunction with visual and audio stimuli, to govern the design of a commercial personal entertainment simulator for use by members of the public. Investigations revealed that there is currently no existing system comparable to this proposed simulator. Therefore, various fields were researched, including robotics, physiotherapy, virtual reality, haptics and existing simulators; with a view to combining elements of these fields for the development of a manipulation system appropriate to public entertainment use. A survey was conducted on members of the public to investigate their experiences of sports, theme park rides and virtual reality; their personalities; and their opinions of the proposed simulator. This survey indicated that the likely users of such a system would be sensation-seeking, physically active people. The activities which generated the most interest were those which were hazardous, difficult, or required long distance travel. To be consistent with these findings, practical trials were undertaken using the sport of skiing as the context for conducting practical investigations into postural manipulation. Existing and original studies of the movements involved in skiing revealed the complexity of this activity, and the variety of techniques employed by different skiers. These findings, combined with the survey data and earlier investigations, led to the development of a versatile prototype system which could accommodate this variability and impose customised skiing movements on volunteers. Volunteer trials using this prototype demonstrated that members of the public were willing to have their postures controlled by external forces, and although some participants were apprehensive at first, they all reported the experience to be enjoyable. Tests with different applied movements showed that users were comfortable with manipulations at speeds and accelerations up to and exceeding those employed in skiing for real. The principal criteria concluded from these trials were that it is possible to safely and comfortably manipulate human postures through external technology, and that this external control can be used to provide an enjoyable and exhilarating entertainment experience.
13

Visual-haptic integration during tool use

Takahashi, Chie January 2012 (has links)
To integrate visual and haptic information effectively, the brain should only combine information that refers to the same object. Thus, it must solve a 'correspondence problem', to determine if signals relate to the same object or not. This could be achieved by considering the similarity of the two sensory signals in time and space. For example, if two size estimates are spatially separated or conflicting, it is unlikely that they originate from the same object; so sensory integration should not occur. Humans are adept at using tools such as pliers, however, which can systematically change the spatial relationships between (visual) object size and the opening of the hand. Here we investigate whether and how the brain solves this visual-haptic correspondence problem during tool use. In a series of psychophysical experiments we measured object-size discrimination performance, and compared this to statistically optimal predictions, derived from a computational model of sensory integration. We manipulated the spatial offset between seen and felt object positions, and also the relative gain between object size and hand opening. When using a tool, we changed these spatial properties by manipulating tool length and the pivot position (for a pliers-like tool). We found that the brain integrates visual and haptic information near-optimally when using tools (independent of spatial offset and size- conflict between raw sensory signals), but only when the hand opening was appropriately remapped onto the object coordinates by the tool geometry. This suggests that visual-haptic integration is not based on the similarity between raw sensory signals, but instead on the similarity between the distal causes of the visual and haptic estimates. We also showed that perceived size from haptics and the haptic reliability were changed with tool gain. Moreover, cue weights of the same object size were altered by the tool geometry, suggesting that the brain does dynamically take spatial changes into account when using a tool. These findings can be explained within a Bayesian framework of multisensory integration. We conclude that the brain takes into account the dynamics and geometry of tools allowing the visual-haptic correspondence problem to be solved correctly under a range of circumstances. We explore the theoretical implications of this for understanding sensory integration, as well as practical implications for the design of visual-haptic interfaces.
14

Factors that influence the receptivity to fault diagnostic learning when a systems approach is applied : a technical transfer study

Craig, Malcolm January 1992 (has links)
This thesis is concerned with receptivity and response encountered at different levels within organisations when a novel approach to the learning of fault diagnosis skills is introduced. Essentially, the work involved the transfer of a learning technology from research and development on the one hand to the workplace on the other. With only a few exceptions, previous research had taken a highly focused, machinecentred view of fault diagnosis. The same view has been adopted towards the limited range of training that is currently offered in this subject. The overall aim here was to introduce a holistic approach by viewing fault diagnosis as a social process that is conducted within a technical context. To do this, account had to be taken of the complex interactions found between a number of disciplines such as, design, production, quality assurance, buying, maintenance and management. The learning technology that served as a vehicle for the transfer of this systems approach was a series of open learning modules. The modules were produced as part of the project. The methodology was based upon an inductive approach that involved the interpretation of qualitative data; this was done using a triangulation of research methods: case studies, critical incidents, and survey questionnaire. The sample, of both large and small organisations, was designed to provide a mix of different types of manufacturing and service industries. In each case, the practice of fault diagnosis skills continues to be a critical influence upon business performance. Different factors arose at different levels within each organisation, and betweenorganisation factor differences are also identified. Apart from the production of open learning material, the contribution made to the subject area is of new insights into the mechanism used for technology transfer within companies, and the identification of factors that either facilitate or hinder transfer of this kind. There is also a contribution to the debate about how the theory of systems thinking can be applied in a prescriptive way as opposed to the more common descriptive delivery. Recommendations are made for further developmento f the learning technology.
15

The evaluation of drivers responses to a multi-characteristic power assisted steering system

Anderson, J. M. January 1982 (has links)
A sample of fifty male and fifty female drivers took part in an:. experiment designed to evaluate a multi-characteristic power assisted steering system. Subjects drove a car fitted with the system for two one-hour periods on public roads and on two test-track sessions during which a number of driving performance variables including driving time and steering activity were recorded. Drivers completed a specially developed questionnaire after each road drive. A subsidiary task, which involved the visual monitoring of an illuminated display and verbal responses, was administered during the test-track sessions. Factor analysis and discriminant analysis were used to analyse data from the questionnaire, road drives and test- track sessions. Data were first factor analysed and the factors subsequently used as variables in the discriminant analyses. It was possible to discriminate between male and female drivers, and between groups of drivers allocated to the different power steering characteristics on the basis of the discriminant functions derived. Thus, reales were found to be more sensitive to the force feedback characteristics of the standard power steering than females, finding it difficult to judge the amount of effort required to steer the car and tending to 'over steer' under some circumstances. Males drove faster than the females on the Motorway with the standard power steering, however, more slowly than females in urban driving, and drove faster and more accurately than females on the test-track. On the basis of the differences observed between drivers allocated to the different power steering characteristics, criteria were developed which allowed the specification of that characteristic which could be considerec 'optimal' for ordinary drivers of both sexes. This character- istic, termed 'Speed Proportional Feel', provides the driver with full power assistance at low speeds, but increasingly inhibits the operation of the power assistance as vehicle speeds rise, giving more steering 'feel' at high speeds. The test-track data were further analysed by means of the analysis of variance and analysis of covariance. The results of the analysis of variance indicated that the presence of the subsidiary task had affected drivers' performance on the test-track. Analysis of covariance was used to provide a statistical control for the effects of the subsidiary task on drivers' primary task performance and a significant learning effect was observed. No significant differences were found in the number of subsidiary task responses made by drivers allocated to different steering characteristics. A recommendation was made for further research into the observed differences between males' and females' driving speeds which, it was suggested, may be related to the types of accident in which males and females are typically involved. Further research into the level of artificial 'feel' favoured by male and female-drivers was also recommended on the basis of the finding that females appeared to respond more favour- ably to a lower level of 'feel' than males.
16

An ethnographic exploration of factors mediating the relationship between gender and skill in a software R&D unit

Woodfield, Ruth January 1994 (has links)
No description available.
17

Human-computer collaborative learning

Dillenbourg, Pierre J. January 1991 (has links)
No description available.
18

Towards socio-technical prototyping via action simulation

Martin, John January 1992 (has links)
No description available.
19

Improvements to the design of the hand hoe and its potential for adoption in Nigeria

Bassi, Sule Yakubu January 1992 (has links)
No description available.
20

An expert system approach to project management support

Ibrahim Ali, M. A. January 1993 (has links)
No description available.

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