No description available.

Little information is available in the literature concerning an ergonomic systems view of industrial seats. This study has been aimed at expanding knowledge of industrial seat design. For this purpose, a model for evaluating industrial seats has been proposed, listing demands and restrictions from the task and the workplace. It also includes responses and effects on the sitter, and methods of measurement for evaluating industrial work seats. The appropriateness of work seat design has been assessed in laboratory and field studies, using methods to measure body loads, their effects and responses. These have been body height shrinkage, biomechanical methods, subjective assessment, and posture assessment. The shrinkage method, including equipment and procedures, has been developed in this project. It assesses the effect of loads on the spine in vivo by using body height changes as a measure of disc creep. The results are well correlated with spinal loads. The method is sensitive enough to differentiate between spinal loads of 100 N difference. The results are also related to the perception of discomfort. Biomechanical methods have been developed for calculating compressive, shear, and momental loads on the spine. Ratings of discomfort, body mapping, interviews, video recordings, and prototype equipment for the recording of head posture have also been used. The methods have been shown to be appropriate for seat evaluation. Work seats have been evaluated in different tasks, incorporating back-rests of different height, width and shape, conventional seat pans and sit-stand seats. It has been shown that advantageous chair features could be referred to each particular task. The tasks evaluated included forward force exertion (high backrests advantageous), vision to the side (low backrests advantageous), work with restricted knee-room (seats allowing increased trunk-thigh angle advantageous), grinding (high, narrow backrests advantageous), punch press work (increased seat height advantageous), and fork lift truck driving (medium height backrest advantageous). The work task has been shown to be a major influence on seat design, and must therefore always be thoroughly considered.

This thesis deals with theoretical and practical issues of special-purpose keyboard design and operator training precedures. It is in two parts.The research discussed in Part A was carried out in support of two contracts from the Post Office and had two main objectives: first, to provide information needed for the selection of a new keyboard design for use on foreign destination coding desks and second, to evaluate one component of a computerbased training system for operators of the new keyboard.In relation to the first objective, four keyboard designs were evaluated, namely the 2x6,4x4,10-key chord and 10-key sequential. On the basis of the results of three experiments, the 10-key chord keyboard was chosen and recommended to the Post Office as the most efficient of the four layouts.The computer-based training system for operators of foreign destination letter coding desks consists of three stages. In this thesis only the first such stage is discusssed, namely the Keyboard Familiarization, which involves developing the skill of keying chord patterns. Four different computer-based training methods are presented, discussed and evaluated in an experiment specifically designed for this purpose.The main issue of Part B is speed-accuracy tradeoff relationships in a keyboard task. Following a discussion of the limitations of typical Choice Reaction Time models and the benefits of studying speed-accuracy tradeoff relationships, another analysis of the data of Experiment 4 is presented. In this analysis, the speed and accuracy of any given response are examined in terms of those of the preceding response.These findings are discussed in the light of established theories and it is concluded that no known theory can fully account for the obtained results. A new theoretical model is presented to explain them. Finally, this new model is assessed and its implications for keyboard operation and operator training are considered.

No description available.

No description available.

No description available.

No description available.

No description available.

This thesis contains six studies investigating the impact of advanced in-vehicle information systems on the visual demands of the driver. The experiments, while self-contained were conceived to relate together in a cohesive manner. The first study investigated the reliability of visual behaviour assessment. Video tape records from experimental trials were analysed post-hoc. Significant test/retest correlations were obtained. Experiment two considered the visual demands of the driving task without intervention from new technologies. Results from road trials using an instrumented vehicle suggested changes in the subject's visual scanning which could be related to the roadway environment (i.e., rural, urban and motorway driving). In experiment three the effects of the introduction of a driver information system were assessed using a congestion warning device on public roads. System use resulted in significantly greater: subjective mental workload, glance duration and frequency, and percentage time (eyes) away from the forward view; than the in-car entertainment system, or the control (normal driving). Experiment four replicated experiment three in a fixed base driving simulator. It aimed to establish the value of the simulator for the assessment of driver visual demand. The same significant differences presented in the road trial were observed in the simulation study. In the penultimate study, opportunities for the reduction of driver visual demand were investigated. The subjects were presented with: visual, auditory or visual and auditory route guidance information. Results suggest use of auditory information to supplement visual displays significantly reduces visual demand on the driver. The final study considered the effect of information availability on the distribution of visual scanning. Driver control of in-vehicle information presentation enabled self-determination of visual scanning strategies. Information system control of information presentation was found to disrupt the driver's visual checking. The interface design was shown to force the driver to adopt different visual scanning strategies. The contribution of the experimental work to the assessment of driver visual demand is discussed and the relationships between the experiments explored.

This thesis presents the initial exploratory research into an original and novel technique to enhance performance control in animatronics. An animatronic system is defined as a 3-D electro-mechanically driven facial model that can move in certain ways, when controlled by a human performer to create the "illusion of life" for a viewer. The vital elements in this form of performance are the synchronisation of lip movements to an acoustic speech signal and the animation of emotive expressions. A novel optical sensing technique is proposed based on the hypothesis that the input of distinctive articulatory or emotive movements from the performer's face would provide a more 'natural' form of control. The principle that the movement of a minimal set of points at key positions on the face can produce sufficient control information to describe the overall action is proposed to achieve this hypothesis. A comprehensive investigation into human communication, including visual speech perception and non-verbal facial expression, to define the optimum set of key points is described. Conclusions are also drawn on the primary facial actions required for successful lip synchronisation. Both the theoretical and practical aspects of the realisation of a prototype system are described. A methodology is presented for the assessment of the sensing system and the overall objectives based on the design and construction of an animatronic face, of the same dimensions as the researcher's, to produce animation of the desired actions with similar displacements. Objective analysis is achieved through the comparison of measurements by the sensor system from the performer's key point movements and those of the animatronic model. Perceptual data is generated through the visual analysis of the animated facial movement. The results and analysis of the investigations are presented in the thesis. The thesis discusses results obtained which indicate that, given certain valid assumptions, the sensor system is capable of consistent facial motion detection. It can provide sufficient control for the animatronic model to produce a limited set of facial actions in a realistic manner. Results indicate the possibilities for improved lip synchronisation and, hence, "overall character" performance.