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This thesis presents sets of technologies for enacting multi-agent based decentralised workflow systems. Its purpose is to tackle some of the existing problems in the conventional workflow research from the system architectural and engineering point of view. Some of the problems addressed at the beginning of this thesis have affected the wide deployment of workflow management system in an open environment (internet). This thesis argues that most of these problems are caused by the huge conceptual gap and design rationale between high level application requirements and low level system design/implementation. Specifically, it is argued that the conventional system architecture of workflow management system (client-server) could be replaced by a multi-agent based platform which is more open, collaborative and can better reflect workflow’s distributed features in the open environment. Combining existing workflow design rationale and multi-agent computing technology, a multi-agent based decentralised workflow approach is proposed in this thesis. The architecture of the intended system removes both the centralised data storage and the centralised workflow engine from the system. To achieve this goal, approaches that bridge the gap between the business process modelling and multi-agent interaction protocol production are proposed using three different techniques (namely functional properties based specifications verification, syntax based language mapping and interpretation based communication) according to the different types of business process models used. Based on such approaches, the mechanisms for decentralised process execution are explored. Moreover, our system is also able to be extended to support incompletely/partially specified processes in a distributed manner. The approach for handling such incomplete/partially specified processes at run-time are presented in this thesis. The main contributions of this research are to provide approaches for enabling decentralised workflow systems in an open environment based on a multi-agent platform without changing the conventional workflow design rationale and with maximum use of existing process models and tools.

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This thesis is an account of an investigation into the problems associated with the production of patterns to ensure a garment of satisfactory fit. Essentially, the method described in this thesis consists of defining a number of crucial shaping points on the body and measuring their spatial co-ordinates. A method is then developed which translates these three-dimensional co-ordinates into patterns whose shapes are such that when joined together with darts suitably positioned, the two dimensional pieces of cloth cut from them are transformed into a threedimensional garment of accurate fit. A computer program has been developed which will: (i) read the three-dimensional co-ordinates of the human body, (ii) calculate the accurate angle of dart needed to be inserted into the pattern to convert it into a three-dimensional'shell', (iii) plot a full size skin and/or block pattern which when sewn into a garment will fit the measured body perfectly.

The final objective of the present work is the accurate prediction of the dynamic stiffness behaviour of complex rubber parts using finite element simulation tools. For this purpose, it becomes necessary to perform a complex rubber compound material characterisation and modelling work; this needs two important previous steps. These steps are detailed in the present document together with a theoretical review of viscoelastic visco-elasto-plastic models for elastomers. Firstly, a new characterisation method is proposed to determine the degree of cure of rubber parts. It is known that the degree of cure of rubbers bears heavily on their mechanical properties. This method consists of the correlation of swelling results to rheometer data achieving a good agreement. Secondly, the influence of the strain rate used in static characterisation tests is studied. In this step, a new characterisation method is proposed. The latter characterisation method will be used to fit extended hyperelastic models in Finite Element Analysis (FEA) software like ANSYS. The proposed method improves the correlation of experimental data to simulation results obtained by the use of standard methods. Finally, the overlay method proposed by Austrell concerning frequency dependence of the dynamic modulus and loss angle that is known to increase more with frequency for small amplitudes than for large amplitudes is developed. The original version of the overlay method yields no difference in frequency dependence with respect to different load amplitudes. However, if the element in the viscoelastic layer of the finite element model are given different stiffness and loss properties depending on the loading amplitude level, frequency dependence is shown to be more accurate compared to experiments. The commercial finite element program Ansys is used to model an industrial metal rubber part using two layers of elements. One layer is a hyper viscoelastic layer and the other layer uses an elasto-plastic model with a multi-linear kinematic hardening rule. The model, being intended for stationary cyclic loading, shows good agreement with measurements on the harmonically loaded industrial rubber part.

The effect of changing processing conditions on the mechanical properties of LDPE, LLDPE and blends of LDPE and LLDPE blown films was studied. The results were analysed by relating the change in mechanical properties with the change in the residual strain of manufactured film. The residual strain was measured by using a shrinkage method.