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Intelligent and integrated architectural design can substantially reduce carbon dioxide emissions from energy used in buildings. However, architects need new tools to help them to design enjoyable, comfortable, attractive and yet technically rigorous, low energy buildings. This thesis investigates, by means of a Research Through Design approach, how architectural software could be better designed to fulfil this need by the integration of design, energy simulation and decision support systems. The problem domain of the design of buildings with very low energy requirements was analysed. Two case studies were employed to investigate the limitations with current software. User and domain software requirements were recorded and analysed. Conflicting requirements were noted, in particular, dichotomous views of the building model. An investigation was carried out into the different interoperable standards that result in these views and rules on how to compose the building model as a series of Intelligent Spaces proposed. The Intelligent Spaces would be abstract volumes, enclosed by zero thickness surfaces, which have data and rules attached. Early prototyping of integrated software was carried out by means of a series of sketches and diagrammatic examples. The novel feature of the proposal is that it maintains both an abstract and detailed version of the building model through all stages of the building design and use. Key features of the proposed software are: 1) the ability to move iteratively between sketch to detailed design to explore different approaches to the building form and construction, 2) the setting and monitoring of relevant energy targets throughout the different building design stages and 3) the integration of an advisory system linked to energy targets to support decision making. This space based approach to the software has the potential to provide a ‘designerly’ front to the sophisticated processes of a Building Information Modelling environment.

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Computer Aided Design (CAD) is a tremendously powerful tool within the design industry, yet when used inappropriately, can be a hindrance to product designers. Employing ineffective CAD modelling strategies (CMS) can lead to increased project costs as a result of an unnecessary amount of time being spent making design changes to the product. However, when CMS are implemented effectively, it has been shown that novice CAD users can not only create an accurate three-dimensional (3D) representation of a product, but are able to make key design changes quickly and effectively (a skill often associated with practiced CAD users). The submission detailed herein documents the development of 3D CAD modelling strategies and the investigation into their impact on novice users. The submission has been split into eleven chapters. The subject is introduced in Chapter One, where the background and structure of the research is considered, as well as the implications of lack of CAD experience for novice CAD users. Some initial research aims were generated, which are examined in the Exploratory Study detailed in Chapter Two. This includes an exploratory review of literature together with details of the initial studies involving CAD users, where it was found that there were potential benefits of communicating CMS to novice CAD users. Having examined the prior art in the field, a theme emerges regarding the benefits of communicating CMS to product designers and focused research aims are presented. The research methodology is considered in Chapter Three, which outlines the databases built to manage the periodic review of literature, to ensure that methodologies were in place to draw meaningful results from the data, both qualitative and quantitative. The pilot study, used to understand how designers implemented strategies when modelling on CAD is discussed in Chapter Four, which lead to the definition of the content of the CAD Modelling Strategies Support (CMSS) material in Chapter Five. Following this, a systematic review of literature on the subject of teaching and learning is discussed in Chapter Six, including pedagogical issues such as the Experiential Learning Theory and visualisation, where a blended learning approach was identified as being the most appropriate method with which to present the CMSS material. The CMSS material was then piloted a number of times within the Pilot Study Two phase detailed in Chapter Seven. The final CMSS material is then outlined in Chapter Eight, which was later evaluated against the emergent theme, as documented in Chapter Nine. The discussion continues in Chapter Ten where it was found that the participants exposed to the CMSS material had used a more effective strategy to model a product on CAD than those who did not use the material (the Control Group). This resulted in them being able to make key design changes to their models in approximately half the time of the Control Group. It was found that the CMSS material produced competent CAD users who could easily make design changes to their models, which inferred implications on the teaching and learning of CAD. Overall conclusions and recommendations relating to the research are drawn in Chapter Eleven that, again, bear direct relevance to how product designers learn to use CAD.

This thesis examines four main subjects; consumer federated Internet Identity Management (IdM), text analysis to detect grooming in Internet chat, a system for using steganographed emoticons as ‘digital fingerprints' in instant messaging and a systems analysis of online child protection. The Internet was never designed to support an identity framework. The current username / password model does not scale well and with an ever increasing number of sites and services users are suffering from password fatigue and using insecure practises such as using the same password across websites. In addition users are supplying personal information to vast number of sites and services with little, if any control over how that information is used. A new identity metasystem promises to bring federated identity, which has found success in the enterprise to the consumer, placing the user in control and limiting the disclosure of personal information. This thesis argues though technical feasible no business model exists to support consumer IdM and without a major change in Internet culture such as a breakdown in trust and security a new identity metasystem will not be realised. Is it possible to detect grooming or potential grooming from a statistical examination of Internet chat messages? Using techniques from speaker verification can grooming relationships be detected? Can this approach improve on the leading text analysis technique – Bayesian trigram analysis? Using a novel feature extraction technique and Gaussian Mixture Models (GMM) to detect potential grooming proved to be unreliable. Even with the benefit of extensive tuning the author doubts the technique would match or improve upon Bayesian analysis. Around 80% of child grooming is blatant with the groomer disguising neither their age nor sexual intent. Experiments conducted with Bayesian trigram analysis suggest this could be reliably detected, detecting the subtle, devious remaining 20% is considerably harder and reliable detection is questionable especially in systems using teenagers (the most at risk group). Observations of the MSN Messenger service and protocol lead the author to discover a method by which to leave digitally verifiable files on the computer of anyone who chats with a child by exploiting the custom emoticon feature. By employing techniques from steganography these custom emoticons can be made to appear innocuous. Finding and removing custom emoticons is a non-trivial matter and they cannot be easily spoofed. Identification is performed by examining the emoticon (file) hashes. If an emoticon is recovered e.g. in the course of an investigation it can be hashed and the hashed compared against a database of registered users and used to support non-repudiation and confirm if an individual has indeed been chatting with a child. Online child protection has been described as a classic systems problem. It covers a broad range of complex, and sometimes difficult to research issues including technology, sociology, psychology and law, and affects directly or indirectly the majority of the UK population. Yet despite this the problem and the challenges are poorly understood, thanks in no small part to mawkish attitudes and alarmist media coverage. Here the problem is examined holistically; how children use technology, what the risks are, and how they can best be protected – based not on idealism, but on the known behaviours of children. The overall protection message is often confused and unrealistic, leaving parents and children ill prepared to protect themselves. Technology does have a place in protecting children, but this is secondary to a strong and understanding parent/child relationship and education, both of the child and parent.

This thesis, first of all, proposes a new data mining paradigm (transaction-filtering association rule mining) addressing a time consumption issue caused by the repeated scans of original transaction databases in conventional associate rule mining algorithms. An in-memory transaction filter is designed to discard those infrequent items in the pruning steps. This filter is a data structure to be updated at the end of each iteration. The results based on an IBM benchmark show that an execution time reduction of 10% - 19% is achieved compared with the base case. Next, a data mining-based predictive model is then established contributing to intelligent data management within the context of Centre for Grid Computing. The capability of discovering unseen rules, patterns and correlations enables data mining techniques favourable in areas where massive amounts of data are generated. The past behaviours of two typical scenarios (network file systems and Data Grids) have been analyzed to build the model. The future popularity of files can be forecasted with an accuracy of 90% by deploying the above predictor based on the given real system traces. A further step towards intelligent policy design is achieved by analyzing the prediction results of files’ future popularity. The real system trace-based simulations have shown improvements of 2-4 times in terms of data response time in network file system scenario and 24% mean job time reduction in Data Grids compared with conventional cases.

Coercive subtyping is a useful and powerful framework of subtyping for type theories. In this thesis, we point out the problem in the old formulation of coercive subtyping in [Luo99], give a new and adequate formulation T[C], the system that extends a type theory T with coercive subtyping based on a set C of basic subtyping judgements, and show that coercive subtyping is a conservative extension and, in a more general sense, a definitional extension. We introduce an intermediate system, the star-calculus T[C]*, in which the positions that require coercion insertions are marked, and show that T[C]* is a conservative extension of T and that T[C]* is equivalent to T[C]. Further more, in order to capture all the properties of the coercive subtyping framework, we introduce another intermediate system T[C]OK which does not contain the coercion application rules. We show that T[C]* is actually a definitional extension of T[C]OK, which is a conservative extension of T. This makes clear what we mean by coercive subtyping being a conservative extension and amends a technical problem that has led to a gap in the earlier conservativity proof. Another part of the work in this thesis concerns the implementation of coercive subtyping in the proof assistant Plastic. Coercive subtyping was implemented in Plastic by Paul Callaghan [CL01j. We have done some im- provement based on that work, fixed some problems of Plastic, and imple- mented a new kind of data type called dot-types, which are special data types useful in formal semantics to describe interesting linguistic phenomena such as copredication, in Plastic.