The concept of Information Architecture (IA) has been independently explored by researchers and practitioners in Information Engineering, Information Systems (ISmanagement, information visualisation and Web site design. However, little has been achieved towards its standardisation within and across these subject domains. To bridge the existing subject divide this study conducts a systematic analysis of publications on frameworks for Information Architecture developed in the field of IS planning and Information Engineering and elicits both common and desirable IA dimensions. It concludes that regardless of their originating subject field, existing IA frameworks are internally focused and have limited effectiveness for dynamic e-business alliances. To address this deficiency, related subject domains such as Systems Theory and Systems Modelling, Web design and virtual team working are explored and ideas are generated for further architectural components such as events, standards, aggregation level and trust that are not supported by existing IAs, but are of high importance for e-business. These are synthesized with the most prevalent IA dimensions identified earlier into a conceptual framework for IA for electronically mediated business networks, called FEBus ffra. network for Information Architecture for Electronically mediated Business networks. The structural viability and usability of the proposed analytical vehicle are evaluated over the period 2001-2003 using a triangulation of a Delphi study, an electronic survey, and evaluation interviews. The participants, representing three self-selecting samples of experienced UK academics and practitioners interested in IA, confirmed the need for an IA framework for e-business alliances and proposed and proved the scope, merits and limitations of the tool. Their views formed the basis for some amendments to the framework and for recommendations for future research. This thesis presents an original contribution to IA knowledge through the comprehensive critical analysis of frameworks on IA and the development of a set of fundamental requirements for IA for e-business environments. Its importance is also seen in the synthesis of the research on 1A conducted in different subject areas. The architectural tool built as an extension of the reviewed IA works constitutes another original aspect of this research. Finally, the novel multi-method evaluation approach employed in the study and the critical examination of its operability, present an advancement of existing knowledge on methodological diversity in IS research.

The use of mathematical models and associated computer simulation is a well established technique for predicting the behaviour of large marine vessels. For a variety of reasons, mainly related to effects of scale, existing models are unable to adequately predict the manoeuvring characteristics of smaller vessels. The accuracy with which the performance of a boat under autopilot control can be predicted leaves much to be desired. The thesis provides a mathematical model to simulate small boat behaviour and so can assist with the design and testing of marine autopilots. The boat model is presented in six degrees-of-freedom, which, with suitable wave disturbance terms, allows motions such as broaching to be analysed. Instabilities in the performance of an autopilot arising from such sea induced yaw motions can be assessed with a view to improving the control algorithms and methodology. The traditional "regressional" style models used for large ships are not suitable for a small boat model since there exist numerous small boat types and diverse hull shapes. Instead, a modular approach has been adopted where individual forces and moments are categorised in separate sections of the model. This approach is still in its infancy in the field of marine simulation. The modular concept demands a clearer understanding of the physical hydrodynamic processes involved in the boat system, and the formulation of equations which do not rely solely upon approximations to, or multiple regression of, data from sea trials. Although many hydrodynamic coefficients have been introduced into the model, a multi-variable Taylor series expansion of the states about some equilibrium condition has been avoided, since this would infer an approximation to have been made, and the higher order terms rapidly become abstract in their nature and difficult to relate to the real world. The research rectifies the glaring omission of a small boat mathematical model, the framework of which could be expanded to encompass other marine vehicles. Additional forces and moments can be appended to the model in new modules, or existing modules modified to suit new applications. Much more work, covering a greater range and fidelity, is required in order to provide equations which accurately describe the true physical situation.

The primary purpose of this research is to explore the relationships between Beer's viable system model (VSM) and mainstream functionalist organisation theory.The latter is taken to include the classical, behavioural and systems models of organisation. For completeness, we also consider organisation theory situated in the interpretive, radical humanist and radical structuralist paradigms of Burrell and Morgan's (1979) sociological grid. Models of mainstream organisation theory have been used extensively by organisation theorists in the structuring of organisations and the design of information systems. Little interest, however, has been paid by organisation theorists to Beer's VSM, which is also used by cyberneticians to structure organisations and design information systems. The problem is that both camps have developed in isolation from one another. Theorists in each camp advocate their own stance regardless what the other might have to offer to their thinking. This situation is a result of a gap between the two camps owing to lack of dialogue between them. The aim of this thesis is to attempt to bridge the gap between the two camps. It is the author's firm belief that this is best done by adopting a complementary approach to pinpoint domains of support each camp may offer to the other. The outcome of this approach is an enhanced model of organisation. Part One of the research begins by introducing the science of cybernetics. Its history, tools, techniques and concepts are then put in place. Building on cybernetic tools and techniques, Beer developed a model of any viable system. Beer's VSM is presented in Chapter 2. Part Two of the thesis is totally devoted to organisational theory. First, we take up models of the functionalist mainstream organisation theory. The approach adopted is first to elaborate on each model, then to contrast each with the VSM. Attention is then directed to organisation theory located in the alternative paradigms, that is, the interpretive, radical humanist and radical structuralist paradigms, respectively. Again, theory of organisation within the above mentioned paradigms is contrasted with the VSM. We mark the end of Part Two by presenting an enhanced model of organisation. This model is the outcome of the comparison which took place between the functionalist organisation theory and the VSM. The argument is that the likelihood of the classical model providing support to the VSM is slim. In fact, the former stands to gain much from the VSM, particularly from the notion of recursive structures which explains how control and communication systems must be designed and organised. The behavioural model, which takes the informal aspects of organisation as its core, appears to be a useful adjunct to the VSM, which concentrates primarily on the formal organisation. Again, the behavioural model stands to gain much from the insights offered by the VSM. At least, the view of openness to the environment would surely give the behavioural model a boost in the right direction. However, we focus our interest on the systems model of organisation, specifically, the notion of semiautonomous work groups encapsulated in the sociotechnical systems approach. By incorporating this notion into the VSM we can, it is hoped, enhance the VSM. Once again, the insights of the VSM, especially that of recursivity of its structure, is of immense significance. In Part Three, the enhanced model is put to the test. This is done by applying it to an existing pharmaceutical manufacturer. The model proves to be not only practical, but also powerful in highlighting domains requiring attention if the effectiveness and efficiency of the organisation in concern is to improve, which the VSM, on its own, cannot provide.

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Despite the number of approaches established for Multiple Criteria Optimisation Problems, few of them have been developed for the decision making process. This research work proposes a new methodology for the solution of optimisation problems that involve multiple criteria emphasising the Decision-Maker's (DM's) preferences model and the use of evolutionary computation techniques and fuzzy logic. The use of genetic algorithms (GAs) is of vital importance to the development of this research. The use of operations research (OR) techniques and decision analysis is also considered vital. The aim of this project is to provide a definition of hybrid approaches that combine the strengths of GA and decision analysis. For this reason four hybrid models are proposed: 1. The GA-SEMOPS. 2. The fuzzy multiobjective genetic optimiser. 3. The GA-PROTRADE. 4. The interactive procedure for multiple objective optimisation problems. The main characteristics of these approaches are that they handle the DM's preferences in an interactive way and their objective functions are formulated using goal levels and surrogate functions. In order to demonstrate that these models can be used in different optimisation problems they have been applied to different case studies covering examples from environmental systems to land and human resource allocation. Each model was studied in depth, comparing the results found with those available in literature. In the majority of the cases, it was found that they performed better than existing methods. The investigations carried out showed that the proposed hybrid models can be considered as a very powerful tool for the solution of a wide variety of optimisation problems in situations from business to science and engineering.

The dissertation presents the investigation and development of novel adaptive computational techniques that provide a high level of performance when searching complex high-dimensional design spaces characterised by heavy non-linear constraint requirements. The objective is to develop a set of adaptive search engines that will allow the successful negotiation of such spaces to provide the design engineer with feasible high performance solutions. Constraint optimisation currently presents a major problem to the engineering designer and many attempts to utilise adaptive search techniques whilst overcoming these problems are in evidence. The most widely used method (which is also the most general) is to incorporate the constraints in the objective function and then use methods for unconstrained search. The engineer must develop and adjust an appropriate penalty function. There is no general solution to this problem neither in classical numerical optimisation nor in evolutionary computation. Some recent theoretical evidence suggests that the problem can only be solved by incorporating a priori knowledge into the search engine. Therefore, it becomes obvious that there is a need to classify constrained optimisation problems according to the degree of available or utilised knowledge and to develop search techniques applicable at each stage. The contribution of this thesis is to provide such a view of constrained optimisation, starting from problems that handle the constraints on the representation level, going through problems that have explicitly defined constraints (i.e., an easily computed closed form like a solvable equation), and ending with heavily constrained problems with implicitly defined constraints (incorporated into a single simulation model). At each stage we develop applicable adaptive search techniques that optimally exploit the degree of available a priori knowledge thus providing excellent quality of results and high performance. The proposed techniques are tested using both well known test beds and real world engineering design problems provided by industry.

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This thesis studies the introduction of a priori structure into the design of learning systems based on artificial neural networks applied to sequence recognition, in particular to phoneme recognition in continuous speech. Because we are interested in sequence analysis, algorithms for training recurrent networks are studied and an original algorithm for constrained recurrent networks is proposed and test results are reported. We also discuss the integration of connectionist models with other analysis tools that have been shown to be useful for sequences, such as dynamic programming and hidden Markov models. We introduce an original algorithm to perform global optimization of a neural network/hidden Markov model hybrid, and show how to perform such a global optimization on all the parameters of the system. Finally, we consider some alternatives to sigmoid networks: Radial Basis Functions, and a method for searching for better learning rules using a priori knowledge and optimization algorithms.

The notion of mobile agent, a software component that can move autonomously between the different nodes of a network is gaining wide popularity in business and in academia. The term mobile agent was first introduced in 1994. Since then, lots of research has been carried out in various aspects of the newly introduced paradigm. It might even be surprising to know that a recent census reports the existence of more than 70 mobile agent systems. Therefore, there is a need to gather and analyze what has been done so far in this new area. / This survey reviews the field of mobile agents by summarizing the key concepts and giving an overview of the most important implementations. Design and implementation issues of mobile agents are analyzed in general. Some of the most important mobile agent systems are presented and discussed. Java's support for mobile agent development is thoroughly examined. In addition, the role of the Common Object Request Broker Architecture (CORBA) as a broker between mobile agents and their environment is also analyzed. Most importantly, a survey of the major security concerns is provided followed by an analysis of the currently available techniques to address these concerns. Last but not least, a detailed analysis of the Foundation for Intelligent Physical Agents (FIPA) standards for interoperability between heterogeneous agents and their hosts is included. This survey will help in understanding the potentials of mobile agents and why they have not caught on. Once progress is made in the areas of security, programming language support for specific mobile agent requirements, and standards for coordination between heterogeneous agents, it is expected that the mobile agent paradigm will dramatically revolutionize the way the Internet is being used now.