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The study presents a normative framework for the Additive Manufacturing (AM) implementation process in the UK manufacturing sector. The motivations for the study include the lack of socio-technical studies on the AM implementation process and the need for existing and potential future project managers to have an implementation model to guide their efforts in implementing these relatively new and potentially disruptive technologies. The study has been conducted through case research with the primary data collected through the in-depth semi-structured interviews with AM project managers. Seven case studies were conducted representing AM implementation practice at different stages of the implementation cycle. The first stage involved a pilot study at a post-implementer to identify the main areas of interest for AM implementation research. The second involved a wider study of AM implementers at the post-implementation stage with cross case analysis of implementation practice. The final stage involved an investigation into pre-implementation of AM, applying the proposed framework in three companies yet to fully implement AM as a production method. Contribution towards the existing body of literature was in the form of a normative framework for AM implementation in a variety of industrial sectors. The framework describes the main activities in the implementation process and supports a taxonomy of implementers.

A reliable colour appearance model is highly desired by various industries such as textiles, paint, plastic, colour imaging, etc. Five colour appearance models named CAM97s3, CAM97s3c, CAM97s4, CAM97s4c and CAM97s5, which are capable of accurately predicting the colour appearance under different viewing conditions, were developed from this study. They were modified from the current international standard colour appearancem odel CIIECAM97s. A series of extensive psychophysical experiments was conducted to scale the colour appearanceo f object colours using magnitudee stimation methodsu nder twelve phaseso f various viewing conditions in this study. The viewing parameters of the samples included two sizes (large and small), three backgrounds (white, grey and black), two textures (paint and textile) and from perceived colour attributes (lightness, colourfulness, hue and saturation). In total, 40,254 estimations were made. The purposes of this project were: 1. to investigate the influence of the size, background and texture on the perception of three different colour attributes - the lightness, colourfulness and hue; 2. to examine the Helmholtz-Kohlrausch (HK) effect, i. e. the lightness affected by chroma of a sample; 3. to accumulate the saturation experimental data; 4. to test the performanceo f the available colour appearancem odels;a nd 5. to improve existing functions in terms of accuracy and simplicity, and to develop a new saturation scale for the CIIECAM97s type models. This thesisd escribesth e experimentaml ethodsc, ollectiono f the psychophysicadl.a ta, analysis of observer performance and various visual effects. A unique data set in visual experiments was collected and is named the Juan & Luo data set. The results were analyzed and discussed. It, was found that the lightness contrast effect is occurred for both large and small sizes. In general, colours appear darker against a lighter background. The results show that there is no size effect for all three attributes studied: lightness, colourfulness and hue. The textile samples appear slightly lighter and more colourful than the paint samples for all three neutral backgrounds. This study confirmed that the HK effect makes most chromatic colours appear lighter than the neutral colours which have similar luminance. The results also indicate that observers can be trained to scale saturation with a great accuracy. By dividing colourfulness to lightness visual results, a strong correlation between these values and saturation results can be found. Twelve colour appearancem odels were tested using the Juan & Luo results. They can be divided into seven different types: CIELAB, Nayatani, RLAB, Hunt, LLAB, ATD, CIECAM97s. (Each type may have more than one version.) Comparing lightness predictions from different models, ATD and RLAB models slightly outperformed the other models. The CIECAM type models gave the most accurate predictions to the visual colourfulness results amongst all the models tested. All models perform the same good in hue prediction and all gave poor predictions to the data of saturation. Efforts were made to include not just the present but also previously accumulated data sets to derive or modify new scales to improve the performance of the CIECAM97s colour appearancem odel. Finally, five models were achieved:C AM97s3, CAM97s3c, CAM97s4, CAM97s4c and CAM97s5. The former two are more like CIECAM97s, the latter are a simplification of lightness, brightness, chroma, colourfulness and saturation scales to the CIECAM97s. All new models perform nearly the same but CAM97s5 is the best.

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A novel technique of drawing wire, i.e., dieless wire drawing, is described in which no conventional reduction dies are used. The wire is passed through a unit having stepped parallel bores filled with polymer melts, the smallest bore diameter being greater than the initial nominal wire diameter. The technique eliminates the need for a leader wire, prevents breakage during start-up, and eliminates the use of conventional reduction dies and, hence, the problem of die wear. An analysis has been developed for predicting the produced wire sizes for given drawing speeds, the pressure distribution within the unit and the drawing load during the drawing process. The performance of the drawing process is effected by means of the plasto-hydrodynamic action of the polymer melt within the unit. Heat is generated by mechanical dissipation during the drawing process. The effect of this upon the performance of the process is considered by coupling the energy equation into the analysis and allowing the polymer viscosity to be dependent on temperature. Agreement between the theory and experiment is found to be close. To further investigate the performance of the drawing process, an extensive experimental study has been undertaken, in which parameters such as drawing speeds, the temperature of the polymer and type of polymers are varied. Based on the theoretical and experimental results, a microcomputer-based control system for the dieless wire drawing process has been designed and built. A method with which the percentage reduction in area of the wire can be measured on line is proposed. Wires of desired qualities in terms of consistency in diameter over long lengths, or uniform change in area of the wire, are capable of being produced from the new system. A self-tuning controller for determinisic systems is proposed, which has the same structure as a conventional PID controller. The new self-tuning PID controller is based on a generalised self-tuning controller with pole assignment for deterministic systems. Simulation and experimental studies for several examples indicate that the new controller performs well and can be further improved to provide a fundamental method of tuning a PID controller.

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