Model-Driven Engineering (MDE) has been extensively studied. Many directions have been explored, sometimes with the dream of providing a fully integrated approach for designers, developers and other stakeholders to create, reason about and modify models representing software systems. Most, but not all, of the research in MDE has focused on general-purpose languages and models, such as Java and UML. Domain-specific and cross-cutting concerns, such as security, are increasingly essential parts of a software system, but are only treated as second-class citizens in the most popular modelling languages. Efforts have been made to give security, and in particular access control, a more prominent place in MDE, but most of these approaches require advanced knowledge in security, programming (often declarative), or both, making them difficult to use by less technically trained stakeholders. In this thesis, we propose an approach to modelling, analysing and automatically fixing role-based access control (RBAC) that does not require users to write code or queries themselves. To this end, we use two UML profiles and associated OCL constraints that provide the modelling and analysis features. We propose a taxonomy of OCL constraints and use it to define a partial order between categories of constraints, that we use to propose strategies to speed up the models’ evaluation time. Finally, by representing OCL constraints as constraints on a graph, we propose an automated approach for generating lists of model changes that can be applied to an incorrect model in order to fix it. All these features have been fully integrated into a UML modelling IDE, IBM Rational Software Architect.

Design is considered a goal-oriented, problem-solving activity that relies on several key elements namely: human experience, creative thinking and related knowledge. These three key elements if integrated within any design development and accompanied by suitable design methodologies made possible by design computation and advancements in computer technologies can achieve the most creative and competitive results. The reviewed previous research studies discussed specific areas but lacked holistic perspective on creative design systems necessary to support creative design teams throughout the entire design process. The main aim ofthis current research is to address the issue of creative thinking in design from a holistic perspective. Furthermore, to establish a new approach for applying evolutionary computing and visualizing technology in support ofcreative design thinking among design teamsTo achieve this main aim several objectives have been accomplished: (1) investigating existing related areas of research through literature review and interviews, (2) developing a holistic approach for creative design thinking, (3) constructing the overall architecture for a creative design environment to support creative design thinking, (4) developing a novel design computational model to enhance creative design thinking, (5) developing a methodology for creative design model which integrates various necessary elements (6) developing a working prototype using web-technologies, and design computational methods, and (7) validating the developed system through the application of a case study.

No description available.

No description available.

No description available.

No description available.

Optical contouring is a full field, non-contact technique capable of determining shape and deformation data from 3-D surfaces. The data, which are obtained from the optical contouring system, represent the surface geometry at evenly sampled points. The main objective of this thesis is to report some advances achieved by the author in the optical contouring field. Conditions for the design and construction of optical systems to measure object topography and deformation using the same hardware, as well as the optical working methodology and system parameters, are analysed. The conventional in-plane and out-of-plane optical setups for displacement sensitive ESP I systems are employed to contour. The contour maps are obtained by giving small displacements to optical fibres carrying the object and reference beam illumination. A rigorous mathematical treatment of shape contours generated by ESPI is given. It is experimentally verified that the fringe patterns produced are identical to projected fringe contours, and may be analysed in the same way. Then, practical systems which combine deformation and shape measurement in both in-plane and out-of-plane ESPI configuration are demonstrated. Comparison is made with shape measurement using two fringe projection moire techniques. The first moire technique uses electronic demodulation to obtain the contour maps. This technique encodes and analyses moire contours by using an electronic system similar to that used for Electronic Speckle Pattern Interferometry (ESPI). Hence automatic fringe detection and contour measurement is possible. The Talbot effect, where the self imaging of a periodic object is used as second moire technique. The Talbot image of a linear grating is imaged on the target surface. The grating lines are deformed according to the surface shape. Viewing this deformed grating image through a second reference grating, generates contour maps. A novel on-axis sensor which directly measures distance as a direct colour mapping is introduced. It is emphasized that all the techniques researched here can be extended to be applied as industrial tools for surface inspection or quality control. Phase-shift measurement and digital image processing are employed for data reduction.

No description available.

Microfluidics is a relatively new and, with an estimation of the market for these devices exceeding $3 billion in 2014, it is considered a profitable domain. Constant development of new technologies and growing demand for more versatile products cause increasing complexity in this area. To address this, the current trends for the domain include automation, standardisation and customisation. At the same time, the society is moving from product types offering to services. Due to the customisation trend this transition appears beneficial for microfluidics. Taking advantage of these opportunities, an investigation of microfluidic design has been undertaken to address the issues at their origins. The literature review showed a lack of a general design methodology applicable for all microfluidic devices, identified existing approaches as technology driven and the domain as unique in terms of design. Also, it highlighted a number of automation and standardisation attempts in the area. In addition, microfluidics shows limited customer and service-orientation. Meanwhile, an investigation of complexity and its implications in microfluidics narrowed the study to sub-section interactions, which allowed standardisation and automation without compromising customisation. In response to these gaps, an aim of the research is to develop a guideline for service- oriented design of microfluidic devices that can deal with sub-section interactions. This research reviews: existing methodologies for design in micro-scale, their applicability to the domain, microfluidic practitioners’ approach to design, state of service-thinking and services in the area and how sub-section interactions are dealt with for these devices. The developed guideline and design enablers present a proposal for a general process for the design of microfluidics. The solution attempts to tackle the issue of sub- section interactions and brings the domain one step towards an ‘experience economy’ by incorporating service-considerations into the design process. The usefulness of this contribution has been confirmed by a variety of methods and numerous sources including experts in the field.

This thesis presents an experimental investigation into the conditions generated within a high speed bearing system where thermally generated shaft bows can arise from differential journal heating, and under certain condtions this effect has been observed to result in unstable shaft vibration - the ‘Morton Effect’. This thesis documents the development of a simplified analytical procedure for evaluating the thermal activity within an orbiting journal when running in hydrodynamic bearings. The aim of this work was to generate controlled experimental data regarding journal differential heating effects to support the understanding and development of appropriate modelling and predictive techniques. A high speed rotor test rig, running in 50mm diameter bearings of fixed and variable geometry configuration, was used to obtain directly measured temperature distributions within the rotor when running under varying speed and unbalance response conditions. Two separate rotor designs were used. The first is designed as a rigid rotor where no structurally influenced rotor dynamic phenomena are present within the running ranges. The second is a flexible rotor designed to operate in a super critical condition where conditions are replicated to provide a rotor that is sensitive to the variables required for thermal bow development and the rotordyanmic conditions promotional of associated instabilities. Existing theoretical models, in combination with operationally observed characteristics, were used to develop a design predicted to become unstable within the test running range. Journal temperature measurements were obtained for rigid and flexible rotors over a range of speed conditions in intentionally introduced mechanical unbalance conditions. Journal temperature differentials were obtained with a clear correlation between journal orbit size and journal temperature differential. The flexible rotor was operated for prolonged periods of time in the predicted unstable region but instability was never initiated for any test condition. Peak journal temperature differentials were measured as 1.7 oC. A new analytical model for the bearing oil film and journal thermal developments is presented which has reasonable correlation to other published literature.