The Choice Modelling technique is an emerging technique which appears to have strengths relative to other non-market valuation techniques. The latter group are important in the assessment of the tradeoffs involved in environmental and resource use tradeoffs. However, the use of these techniques is often criticised where ethical and moral frameworks are involved, where it is unclear how difficult choices are being framed against each other, or where it is unclear how values change according to the scope of the amenity under consideration The primary focus of the thesis is on the development of the Choice Modelling technique, which provides a richer information set to researchers than other techniques such as Contingent valuation method. However, the richness of this data is offset to some degree by the complexity of application, where careful attention is needed for design, application and analytical stages. In this thesis, a series of four Choice Modelling experiments are reported, as well as two small Contingent Valuation experiments. The Choice Modelling experiments were centred on the estimation of values that Australians might hold for rainforest conservation in Vanuatu. In order to frame and scope the tradeoffs of interest within the broad pool of substitute goods (such as rainforest conservation opportunities in other countries), the Choice Modelling technique appeared more suitable than the single tradeoff preservation of the Contingent Valuation method. The results of Choice Modelling experiments involved sets of parameters indicating that the probability of choice depended on a number of attributes used to make up the conservation profiles together with the influence of unobserved attributes. As a willingness-to-pay variable was included within the attributes making up choice profiles, estimates of value were available by predicting how changes in particular attributes could be offset by changes in the willingness-to-pay variable. The major conclusions of the research presented in the thesis were that the involvement with ethical and moral frameworks does not invalidate the use of non-market valuation techniques, and that the Choice Modelling technique has strengths in relation to scooping and framing issues. In particular, the research demonstrates that the information generated from an experiment can be used in an iterative approach to develop more accurate models of choice. As well, the research shows that the amenity of interest, rainforest conservation in Vanuatu, can have positive values for Australian residents relative to other conservation opportunities.

The aim of Human Computer Interaction or HCI is to both understand and improve the quality of the users' experience with the systems and technology they interact with. Recent HCI research requirements have stated a need for a unified predictive approach to system design that consolidates system engineering, cognitive modelling, and design principles into a single 'total system approach.' At present, few methods seek to integrate all three of these aspects into a single method and of those that do many are extensions to existing engineering techniques. This thesis, however proposes a new behaviour based approach designed to identify usability problems early in the design process before testing the system with actual users. In order to address the research requirements, this model uses a new design notation called Genetic Software Engineering (GSE) in conjunction with aspects of a cognitive modelling technique called NGOMSL (Natural GOMS Language) as the basis for this approach. GSE's behaviour tree notation, and NGOMSL's goal orientated format are integrated using a set of simple conversion rules defined in this study. Several well established design principles, believed to contribute to the eventual usability of a product, are then modelled in GSE. This thesis addresses the design of simple interfaces and the design of complex ubiquitous technology. The new GSE approach is used to model and predict usability problems in an extensive range of tasks from programming a VCR to making a video recording on a modern mobile phone. The validity of these findings is tested against actual user tests on the same tasks and devices to demonstrate the effectiveness of the GSE approach. Ultimately, the aim of the study is to demonstrate the effectiveness of the new cognitive and engineering based approach at predicting usability problems based on tangible representations of established design principles. This both fulfils the MCI research requirements for a 'total system approach' and establishes a new and novel approach to user interface and system design.

The Choice Modelling technique is an emerging technique which appears to have strengths relative to other non-market valuation techniques. The latter group are important in the assessment of the tradeoffs involved in environmental and resource use tradeoffs. However, the use of these techniques is often criticised where ethical and moral frameworks are involved, where it is unclear how difficult choices are being framed against each other, or where it is unclear how values change according to the scope of the amenity under consideration The primary focus of the thesis is on the development of the Choice Modelling technique, which provides a richer information set to researchers than other techniques such as Contingent valuation method. However, the richness of this data is offset to some degree by the complexity of application, where careful attention is needed for design, application and analytical stages. In this thesis, a series of four Choice Modelling experiments are reported, as well as two small Contingent Valuation experiments. The Choice Modelling experiments were centred on the estimation of values that Australians might hold for rainforest conservation in Vanuatu. In order to frame and scope the tradeoffs of interest within the broad pool of substitute goods (such as rainforest conservation opportunities in other countries), the Choice Modelling technique appeared more suitable than the single tradeoff preservation of the Contingent Valuation method. The results of Choice Modelling experiments involved sets of parameters indicating that the probability of choice depended on a number of attributes used to make up the conservation profiles together with the influence of unobserved attributes. As a willingness-to-pay variable was included within the attributes making up choice profiles, estimates of value were available by predicting how changes in particular attributes could be offset by changes in the willingness-to-pay variable. The major conclusions of the research presented in the thesis were that the involvement with ethical and moral frameworks does not invalidate the use of non-market valuation techniques, and that the Choice Modelling technique has strengths in relation to scooping and framing issues. In particular, the research demonstrates that the information generated from an experiment can be used in an iterative approach to develop more accurate models of choice. As well, the research shows that the amenity of interest, rainforest conservation in Vanuatu, can have positive values for Australian residents relative to other conservation opportunities.

The Choice Modelling technique is an emerging technique which appears to have strengths relative to other non-market valuation techniques. The latter group are important in the assessment of the tradeoffs involved in environmental and resource use tradeoffs. However, the use of these techniques is often criticised where ethical and moral frameworks are involved, where it is unclear how difficult choices are being framed against each other, or where it is unclear how values change according to the scope of the amenity under consideration The primary focus of the thesis is on the development of the Choice Modelling technique, which provides a richer information set to researchers than other techniques such as Contingent valuation method. However, the richness of this data is offset to some degree by the complexity of application, where careful attention is needed for design, application and analytical stages. In this thesis, a series of four Choice Modelling experiments are reported, as well as two small Contingent Valuation experiments. The Choice Modelling experiments were centred on the estimation of values that Australians might hold for rainforest conservation in Vanuatu. In order to frame and scope the tradeoffs of interest within the broad pool of substitute goods (such as rainforest conservation opportunities in other countries), the Choice Modelling technique appeared more suitable than the single tradeoff preservation of the Contingent Valuation method. The results of Choice Modelling experiments involved sets of parameters indicating that the probability of choice depended on a number of attributes used to make up the conservation profiles together with the influence of unobserved attributes. As a willingness-to-pay variable was included within the attributes making up choice profiles, estimates of value were available by predicting how changes in particular attributes could be offset by changes in the willingness-to-pay variable. The major conclusions of the research presented in the thesis were that the involvement with ethical and moral frameworks does not invalidate the use of non-market valuation techniques, and that the Choice Modelling technique has strengths in relation to scooping and framing issues. In particular, the research demonstrates that the information generated from an experiment can be used in an iterative approach to develop more accurate models of choice. As well, the research shows that the amenity of interest, rainforest conservation in Vanuatu, can have positive values for Australian residents relative to other conservation opportunities.

Um dos grandes problemas relacionados a modelagem de workflow consiste na utilização de técnicas de modelagem conceitual especificas a cada sistema de workflow, não havendo, dessa forma, urn modelo aceito consensualmente. Esta situação, decorrência do ambiente competitivo neste mercado, leva a não inclusão de muitas características conceitualmente importantes relacionadas a modelagem nos técnicas geralmente utilizadas. Um importante aspecto a ser tratado nos modelos conceituais e a questão da modelagem formal do workflow e que constitui o terra central deste trabalho. Esta dissertação apresenta uma técnica de modelagem de workflow utilizando como modelo de dados referencial o TF-ORM (Temporal Functionality in Objects with Roles Model). Esta técnica desenvolve uma especificação rigorosa de workflow em um nível conceitual, formalizando com a utilização de um modelo técnico seu comportamento interno (cooperação e interação entre tarefas) e seu relacionamento para o ambiente (designação de tarefas de trabalho para executores). Neste modelo, construções são apresentadas para representar, de forma eficiente, a modularização e o paralelismo. Uma linguagem textual de definição de workflow e apresentada. Adicionalmente é apresentada a utilização de descrições formais do workflow para gerar o esquema de dados do workflow e o conjunto de regras para seu gerenciamento. Em adição, o paradigma de regras oferece um formalismo conveniente para expressar computações reativas influenciadas por eventos externos, gerados fora do WFMS (Workflow Manager System). Finalmente é realizada uma analise sobre algumas ferramentas comerciais, procurando validar a praticidade dos modelos conceituais desenvolvidos. Os principais conceitos envolvidos em workflow são descritos e classificados de forma a possibilitar, a validação tanto dos conceitos quanto da modelagem através de um estudo de caso e a utilização de um sistema comercial. / One of the greatest problems in workflow modelling is the use of specific conceptual modelling techniques associated to each workflow system; there is not a consensual accepted model. This situation, a consequence of the strong competitive environment in this market, leads to the non-inclusion of many important conceptual characteristics. This restriction is a consequence of the restricted modelling techniques closely related with implementation models. An important aspect to be considered, and the central subject of this work, is the formal workflow modelling. A modelling technique using the TF-ORM (Temporary Functionality in Objects with Rolls Model) data model is here presented. The modelling technique develops a rigorous specification of workflow at the conceptual level, formalising in one model its internal behaviour (the co-operation and interaction among tasks) and its relationship with the environment (the designation of tasks). In this model, constructions where developed to represent, in an efficient form, the modularity and the parallelism of the activities. A formal language for the workflow definition is presented. Additionally, the use of formal workflow description is used to generate the data flow and rules set for its management. In addition, the rules paradigm offers a convenient formalism to express reactive computations influenced by external events generated outside the Workflow Manager System. Finally a case study is accomplished using some commercial modelling tools, to validate the developed conceptual models practicality.

Although the overall levels of harmonics in modern power supply systems are in most of the practical cases still below the prescribed tolerance limits and thresholds (e.g. these stipulated in [IEC 61000-3-2 and 61000-3-12]), the sources of harmonics are constantly increasing in numbers and are expected to increase even more in the future. Some of the examples of modern non-linear power electronic (PE) devices that are expected to be employed on a much wider scale in LV networks in the future include: light-emitting diode (LED) lamps, switched-mode power supplies (SMPS'), electric vehicle battery chargers (EVBCs) and photovoltaic inverters (PVIs), which are all analysed in this thesis. The thesis first reviews the conventional harmonic analysis methods, investigating their applicability to modern PE devices. After that, the two most widely used forms of harmonic models, i.e. component-based models (CBMs) and frequency-domain models (FDMs), are applied for modelling of the four abovementioned types of modern PE devices and their models are fully validated by measurements. The thesis next investigates the impact of supply voltage conditions and operating modes (e.g. low vs high operating powers) on the device characteristics and performance, using both measurements and developed CBMs and FDMs. The obtained results confirm that both supply conditions and operating modes have an impact on the characteristics of most of the considered PE devices, which is taken into account in the developed models and demonstrated on a number of case studies. As the next contribution, the thesis proposes new indices for the evaluation of current waveform distortions, allowing for a separate analysis of contributions of low and high frequency harmonics and interharmonics to the total waveform distortion of PE devices. As the modern PE devices are normally based on high-frequency switching converters or inverters, the impact of circuit topologies and control algorithms on their harmonic emission characteristics and performance is also investigated. Special attention is given to the operation of PE devices at low powers, when there is a significant increase of current waveform distortion, a substantial decrease of efficiency and power factors and when input ac current might lose its periodicity with the supply voltage frequency. This is analysed in detail for SMPS', resulting in the proposal of a new methodology ("operating cycle based method") for evaluating overall performance of PE devices across the entire range of operating powers. Finally, a novel and simple hybrid harmonic modelling technique, allowing for the use of both time-domain and frequency-domain models in the same simulation environment, is proposed and illustrated on the selected case studies. This is accompanied with a frequency-domain aggregation approach, which is applied in the thesis to investigate the impact of increasing numbers of different types of modern PE devices on the LV network. The implementation of the developed hybrid harmonic modelling approach and frequency-domain aggregation technique is demonstrated on the example of a typical (UK) urban generic LV distribution network and used for the analysis of different deployment levels of EVs and PVIs. The presented harmonic modelling framework for individual PE devices and, particularly, for their aggregate models, fills the gap in the existing literature on harmonic modelling and characterisation of modern PE devices, which is important for the correct evaluation of their harmonic interactions and analysis of the impact of their large-scale deployment on the overall network performance.

Um dos grandes problemas relacionados a modelagem de workflow consiste na utilização de técnicas de modelagem conceitual especificas a cada sistema de workflow, não havendo, dessa forma, urn modelo aceito consensualmente. Esta situação, decorrência do ambiente competitivo neste mercado, leva a não inclusão de muitas características conceitualmente importantes relacionadas a modelagem nos técnicas geralmente utilizadas. Um importante aspecto a ser tratado nos modelos conceituais e a questão da modelagem formal do workflow e que constitui o terra central deste trabalho. Esta dissertação apresenta uma técnica de modelagem de workflow utilizando como modelo de dados referencial o TF-ORM (Temporal Functionality in Objects with Roles Model). Esta técnica desenvolve uma especificação rigorosa de workflow em um nível conceitual, formalizando com a utilização de um modelo técnico seu comportamento interno (cooperação e interação entre tarefas) e seu relacionamento para o ambiente (designação de tarefas de trabalho para executores). Neste modelo, construções são apresentadas para representar, de forma eficiente, a modularização e o paralelismo. Uma linguagem textual de definição de workflow e apresentada. Adicionalmente é apresentada a utilização de descrições formais do workflow para gerar o esquema de dados do workflow e o conjunto de regras para seu gerenciamento. Em adição, o paradigma de regras oferece um formalismo conveniente para expressar computações reativas influenciadas por eventos externos, gerados fora do WFMS (Workflow Manager System). Finalmente é realizada uma analise sobre algumas ferramentas comerciais, procurando validar a praticidade dos modelos conceituais desenvolvidos. Os principais conceitos envolvidos em workflow são descritos e classificados de forma a possibilitar, a validação tanto dos conceitos quanto da modelagem através de um estudo de caso e a utilização de um sistema comercial. / One of the greatest problems in workflow modelling is the use of specific conceptual modelling techniques associated to each workflow system; there is not a consensual accepted model. This situation, a consequence of the strong competitive environment in this market, leads to the non-inclusion of many important conceptual characteristics. This restriction is a consequence of the restricted modelling techniques closely related with implementation models. An important aspect to be considered, and the central subject of this work, is the formal workflow modelling. A modelling technique using the TF-ORM (Temporary Functionality in Objects with Rolls Model) data model is here presented. The modelling technique develops a rigorous specification of workflow at the conceptual level, formalising in one model its internal behaviour (the co-operation and interaction among tasks) and its relationship with the environment (the designation of tasks). In this model, constructions where developed to represent, in an efficient form, the modularity and the parallelism of the activities. A formal language for the workflow definition is presented. Additionally, the use of formal workflow description is used to generate the data flow and rules set for its management. In addition, the rules paradigm offers a convenient formalism to express reactive computations influenced by external events generated outside the Workflow Manager System. Finally a case study is accomplished using some commercial modelling tools, to validate the developed conceptual models practicality.

Um dos grandes problemas relacionados a modelagem de workflow consiste na utilização de técnicas de modelagem conceitual especificas a cada sistema de workflow, não havendo, dessa forma, urn modelo aceito consensualmente. Esta situação, decorrência do ambiente competitivo neste mercado, leva a não inclusão de muitas características conceitualmente importantes relacionadas a modelagem nos técnicas geralmente utilizadas. Um importante aspecto a ser tratado nos modelos conceituais e a questão da modelagem formal do workflow e que constitui o terra central deste trabalho. Esta dissertação apresenta uma técnica de modelagem de workflow utilizando como modelo de dados referencial o TF-ORM (Temporal Functionality in Objects with Roles Model). Esta técnica desenvolve uma especificação rigorosa de workflow em um nível conceitual, formalizando com a utilização de um modelo técnico seu comportamento interno (cooperação e interação entre tarefas) e seu relacionamento para o ambiente (designação de tarefas de trabalho para executores). Neste modelo, construções são apresentadas para representar, de forma eficiente, a modularização e o paralelismo. Uma linguagem textual de definição de workflow e apresentada. Adicionalmente é apresentada a utilização de descrições formais do workflow para gerar o esquema de dados do workflow e o conjunto de regras para seu gerenciamento. Em adição, o paradigma de regras oferece um formalismo conveniente para expressar computações reativas influenciadas por eventos externos, gerados fora do WFMS (Workflow Manager System). Finalmente é realizada uma analise sobre algumas ferramentas comerciais, procurando validar a praticidade dos modelos conceituais desenvolvidos. Os principais conceitos envolvidos em workflow são descritos e classificados de forma a possibilitar, a validação tanto dos conceitos quanto da modelagem através de um estudo de caso e a utilização de um sistema comercial. / One of the greatest problems in workflow modelling is the use of specific conceptual modelling techniques associated to each workflow system; there is not a consensual accepted model. This situation, a consequence of the strong competitive environment in this market, leads to the non-inclusion of many important conceptual characteristics. This restriction is a consequence of the restricted modelling techniques closely related with implementation models. An important aspect to be considered, and the central subject of this work, is the formal workflow modelling. A modelling technique using the TF-ORM (Temporary Functionality in Objects with Rolls Model) data model is here presented. The modelling technique develops a rigorous specification of workflow at the conceptual level, formalising in one model its internal behaviour (the co-operation and interaction among tasks) and its relationship with the environment (the designation of tasks). In this model, constructions where developed to represent, in an efficient form, the modularity and the parallelism of the activities. A formal language for the workflow definition is presented. Additionally, the use of formal workflow description is used to generate the data flow and rules set for its management. In addition, the rules paradigm offers a convenient formalism to express reactive computations influenced by external events generated outside the Workflow Manager System. Finally a case study is accomplished using some commercial modelling tools, to validate the developed conceptual models practicality.