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The main factors which prompted the present study were: (1) PRECIS has a linguistic universal feature for computerized subject indexing; (2) the largest Chinese bibliography and index published by the National Central Library of Taiwan still lack subject indexes; (3) both mainland China and Taiwan have created their bibliographic databases based on UNIMARC; and (4) the field 670 of the UNIMARC is reserved for PRECIS. This study has aimed to experiment with PRECIS for indexing Chinese documents, generate Chinese subject indexes using PRECIS, and suggest the use of PRECIS in online retrieval in Chinese bibliographic databases. The last objective is an assumption which was based on the achievement of the first objective.

The need is expressed for mathematical models which describe the cutting tool-workpiece interaction and for accurate on-line monitoring of tool-state. These are essential requirements for the achievement of unmanned and computerized machining processes. Techniques are used to design the experiments which substantially reduce the number of tests while providing all the essential information for statistical analysis and for the development of mathematical models. The testing conditions are chosen to reasonably conform with the practical requirements. Multi-coated carbide tool inserts [Sandvik GC435] are used to cut an alloy steel [EN 19] under normal cutting conditions and for a wide range of operating parameters. An accurate and sensitive three-component dynamometer was designed, manufactured and used to measure the tool forces through a BBC microcomputer. Continuous records of the tool vibration have been collected in two different co-ordinate directions simultaneously together with measurements of tool wear and cutting forces. Linear and non-linear regression techniques are used to develop mathematical models for the experimentally measured responses: cutting forces, tool vibration, and tool wear. Special attention is devoted to the identification of the most appropriate models. Each model being capable of representing the tool state throughout its working lifetime. Tool life wear-based models are developed to relate the expected tool lifetime to the operating parameters: speed, feed, and depth of cut. A robust regression analysis technique, used in conjunction with iteratively re-weighting least-squares, has been found to improve the accuracy of the models, and to stabilize its computed residuals through the elimination of the effect of influential observations having high experimental error. Response surface methodology RSM has been used to signify the non-linear nature of tool life response. The force variation has been shown to correlate strongly with the wear progress so that it can be used for accurate in-process determination of tool wear and for monitoring tool state. It has been shown that the variation in the ratio between force components correlates with wear and is independent of the effect of other machining parameters; this enables the approach to be used for a wider range of materials and more extensive operational domain. Study of the power spectral analysis of the tool vibration indicates that among the tool's vibration modes, the first fundamental natural frequency of vibration in the feed direction exhibits a consistent correlation with wear-progress. The Vibration amplitude decreases with the increase of the wear level until it reaches a limit after which it tends to reverse its characteristic. The time at which the characteristic changes is found to closely correspond with the practical end of the tool lifetime. Based on this fact, an in-process approach is investigated to determine the tool life on-line. Also, a model has been developed for tool wear estimation based on a combination of vibration and force; and, very good agreement has been obtained with the experimental data. The validity of the models; their feasibility; and, their industrial significance are confirmed for adaptive control AC systems, and for machinability data base systems MDBS.

Modem computerised navigation systems on board ships require an accurate log for optimal performance. Traditional electromechanica1logs on board merchant ships have generally been replaced by Doppler logs, which refer the velocity to the sea-bed. However, their operational depth is limited and in deep water the velocity is referred to the water-mass some depth below the hull, where it is influenced by ocean currents. The velocity accuracy ultimately depends on the estimated local sound velocity. The acoustic correlation log has acoustic beams similar to a conventional depth-sounder, with a vertically downward propagation direction and a broad beamwidth. Compared to the Doppler log it is affected less by ship pitch and roll due to its broad beamwidth, and the velocity is virtually independent of the velocity of sound and is referred to the sea-bed to a greater depth. Temporal correlation logs use a two-hydrophone array and the time delay between the two received signals is used to calculate the velocity. The full potential of these logs for world-wide ocean navigation has not been exploited. This thesis investigates the requirements and conditions for temporal correlation logs on board ships to navigate satisfactorily on and off the continental shelf. An experimental temporal correlation log working at high-frequencies with continuous wave propagation is described. It is used to measure the velocity of a tracked platform moving across a water tank and the results are compared to their theoretical values. When fully developed, the log would be suitable for shallow-water operation, and techniques learned can be applied to a low-frequency deep-water correlation log.

The modern process plant is characterised by the use of computers for process control. Increasing reliability and diminishing capital investment costs have encouraged the use of process computers as the principal control mechanism. Greater reliability has also led to an increase and change in the tasks assigned to the computer. The relatively rapid advances in process control have understandably resulted in a carry-over of traditional practices which are often inadequate in the present day environment. A notable example of such a practice is the alarm system which is neglected in the literature and is frequently the least satisfactory aspect of a control system.