This thesis presents an investigation of braking system characteristics, brake system performance and brake system component design parameters that influence brake pedal force / displacement characteristics as ‘felt’ by the driver in a passenger car. It includes detailed studies of individual brake system component design parameters, operation, and the linear and nonlinear characteristics of internal components through experimental study and simulation modelling. The prediction of brake pedal ‘feel’ in brake system simulation has been achieved using the simulation modelling package AMESim. Each individual brake system component was modelled individually before combining them into the whole brake system in order to identify the parameters and the internal components characteristics that influence the brake pedal ‘feel’. The simulation predictions were validated by experimentally measured data and demonstrated the accuracy of simulation modelling. Axisymmetric Finite Element Analysis (using the ABAQUS software) was used to predict the behaviour of nonlinear elastomeric internal components such as the piston seal and the booster reaction disc which was then included in the AMESim simulation model. The seal model FEA highlighted the effects of master cylinder and caliper seal deformation on the brake pedal ‘feel’. The characteristics of the brake booster reaction disc were predicted by the FEA and AMESim simulation modelling and these results highlighted the importance of the nonlinear material characteristics, and their potential contribution to brake pedal ‘feel’ improvement. A full brake system simulation model was designed, prepared, and used to predict brake system performance and to design a system with better brake pedal ‘feel’. Each of the brake system component design parameters was validated to ensure that the braking system performance was accurately predicted. The critical parameter of brake booster air valve spring stiffness was identified to improve the brake ‘pedal ‘feel’. This research has contributed to the advancement of automotive engineering by providing a method for brake system engineers to design a braking system with improved pedal ‘feel’. The simulation model can be used in the future to provide an accurate prediction of brake system performance at the design stage thereby saving time and cost.

This thesis is focused on a simulation modelling approach to address the inventory inaccuracy problems in a warehouse operation. The main motivation which led to this research was a desire to investigate the inventory inaccuracy issues that have been highlighted by a logistics company. Previous and current research into inventory inaccuracy issues is largely related to the development of RFID technology as a possible solution to inventory problems. Since the inventory inaccuracy related to RFID technology is focused on the overall measurement of inventory management and retail business, there are differences between this existing research and the research presented in this thesis which is focused on issues of inventory inaccuracy in a warehouse operation. In this thesis, warehouse operation is studied as a detailed sequence of processes that are involved in the flow of items physically in parallel with related information being stored in the computer system. In these processes there are many places where errors can occur in counting or recording details of inventory, or in physically moving, storing or picking items incorrectly. These details of a warehouse operation are used to develop a conceptual model of inventory inaccuracy in warehouse operations. The study also found that typically a product needs to be considered differently at different stages of its progress through a warehouse (and therefore within different sections of the conceptual model). This is because initially batches of a product are likely to be delivered from a supplier, therefore if errors occur soon after the product is delivered to the warehouse, the error might involve the whole batch (for example the batch may be misplaced and put in an incorrect storage location), or the error might involve just part of the batch (for example poor transportation by forklift truck may damage the packaging carton and some of the items within the carton). When the product is stored ready for meeting customer orders, it needs to be considered as individual items (and errors can occur in counting of individual items or individual items may be misplaced or stolen). Finally, when a customer order is received, the product will be picked and grouped to meet the requirements of the order (for example, one order may require 10 of the product whilst another order may require 20 of the product). Errors might again occur to the whole group or to just part of the group. (Continued ...)

Much of industry is seeking scope economies, but this requires more complex and flexible product realisation. Modelling technologies have potential to support the life cycle engineering of both Economies of Scope and Scale (EoSS) manufacturing systems. However when companies operate in dynamic environments it is not sufficient to model manufacturing systems in isolation. Rather a holistic modelling methodology is needed which can create structural and behavioural models of dependencies between the manufacturing systems, and the business and engineering environments in which they operate; so that a suitable balance between economies of scope and scale can be achieved. This thesis describes the conception and development of a step wised Extended Modelling Methodology (EMM) which facilitates reasoning, and related decision making, about EoSS manufacturing systems. The EMM was conceived from exploratory research in two SMEs, following which it was applied and case tested in a large manufacturing company. Little academic attention to date has been paid to theorising about the link between ‘Economies of Scope and Scale (EoSS) phenomenon' and ‘manufacturing systems design'. Hence many questions about EoSS manufacturing remain unanswered, such as: (1) academic communities need to know what EoSS actually means and how state-of-the-art modelling can support qualitative and quantitative analysis of EoSS system phenomenon; and (2) industry needs to know how they can benefit from EoSS, what attended costs they might incur, and what best balance between scope and scale economies can be achieved. With these general requirements in mind the thesis reports on the conception and industrial application of the EMM. This has: (A) developed new ideas about EoSS, which can be used to characterise EoSS phenomenon; (B) introduced a new way of visualising architectural aspects of EoSS at multiple-levels of abstraction; and (C) with reference to case studies has illustrated the use of multi-level modelling to enable predictions to be made about EoSS benefits and costs.

This thesis presents an investigation of braking system characteristics, brake system performance and brake system component design parameters that influence brake pedal force / displacement characteristics as ‘felt’ by the driver in a passenger car. It includes detailed studies of individual brake system component design parameters, operation, and the linear and nonlinear characteristics of internal components through experimental study and simulation modelling. The prediction of brake pedal ‘feel’ in brake system simulation has been achieved using the simulation modelling package AMESim. Each individual brake system component was modelled individually before combining them into the whole brake system in order to identify the parameters and the internal components characteristics that influence the brake pedal ‘feel’. The simulation predictions were validated by experimentally measured data and demonstrated the accuracy of simulation modelling. Axisymmetric Finite Element Analysis (using the ABAQUS software) was used to predict the behaviour of nonlinear elastomeric internal components such as the piston seal and the booster reaction disc which was then included in the AMESim simulation model. The seal model FEA highlighted the effects of master cylinder and caliper seal deformation on the brake pedal ‘feel’. The characteristics of the brake booster reaction disc were predicted by the FEA and AMESim simulation modelling and these results highlighted the importance of the nonlinear material characteristics, and their potential contribution to brake pedal ‘feel’ improvement. A full brake system simulation model was designed, prepared, and used to predict brake system performance and to design a system with better brake pedal ‘feel’. Each of the brake system component design parameters was validated to ensure that the braking system performance was accurately predicted. The critical parameter of brake booster air valve spring stiffness was identified to improve the brake ‘pedal ‘feel’. This research has contributed to the advancement of automotive engineering by providing a method for brake system engineers to design a braking system with improved pedal ‘feel’. The simulation model can be used in the future to provide an accurate prediction of brake system performance at the design stage thereby saving time and cost.

A partir de setembro de 1999 até novembro de 2000 estudou-se a várzea da margem direita da planície de inundação do Ribeirão do Feijão, com objetivo de verificação da várzea funcionando como filtro natural na contenção de matéria orgânica utilizando-se para esse estudo, um modelo de simulação desenvolvido com o software Stella. Foram coletados dados climatológicos oriundos de estação climatológica automática (temperatura do ar, umidade relativa, precipitação, radiação solar, velocidade e direção do vento e pressão barométrica), em piezômetros instalados na várzea (em número de 9) e coleta de amostras de água no rio, dados limnológicos: físicos (temperatura da água, turbidez, oxigênio dissolvido, condutividade e profundidade); químicos (fósforo total, fósforo total dissolvido, silicato, nitrogênio total, nitrato, nitrito e amônia), além de dados obtidos pelo estudo da literatura e trabalhos próximos da área de estudo já publicados. A partir do estudo da inter-relação dos processos existentes na várzea de inundação do Ribeirão do Feijão, elaborou-se modelo de simulação. As conclusões que se obtiveram indicam bom comportamento do modelo de simulação e, também, que estudos em escala de tempo mais reduzida sejam utilizados em trabalhos futuros para estudos de várzeas. Outra conclusão refere-se ao funcionamento da várzea como filtro natural, onde houve armazenamento de carbono (matéria orgânica). Constatou-se grande amplitude da variação diária da altura da lâmina d\'água devido à evapotranspiração. Recomenda-se a preservação desse rio porque 40% da água de superfície que abastece a cidade de São Carlos é oriunda desse manancial. / From September 1999 up to November 2000 a wetland of the right margin of Feijão river floodplain was studied with the objective to verify its activity as an natural filter to retain organic matter making use of a simulation model constructed with the help of the Stella software. Were collected climatological data from an automatic climatological station (air temperature, air moisture, rain, solar radiation, speed and wind direction and atmospheric pressure), from piezometers installed within the wetland (number of 9) and samples collected of river water, limnological data: physical data (water temperature, turbidity, dissolved oxygen, conductivity and depth); chemical data (total phosphorus, total dissolved phosphorus, silicate, total nitrogen, nitrate, nitrite and ammonium), moreover data obtained from literature and papers published of sites near the study area. From the interrelationship of processes occurring within the Feijão river floodplain wetland was constructed the simulation model. The obtained conclusions indicate the good simulation model behavior and show that time scales should be shorter in future wetland studies. Other conclusion refer to wetland conduction as a natural filter where occurred carbon storage (organic matter). Great amplitude of water table diary variation have been verified within the wetland due to evapotranspiration. Is possible to recommend the river preservation because 40% of the surface city supply is from this site.

Suite aux réformes des marchés électriques, la question du market design, c’est-à-dire l’étude des nouveaux marchés destinés à remplacer l’ancien monopole, est devenue centrale dans la littérature économique. Toutefois, les caractéristiques techniques de l’électricité rendent cette tâche complexe et l’intervention des pouvoirs publics est souvent nécessaire pour établir les règles du jeu efficaces que les acteurs de marché devront suivre. Cela explique pourquoi le market design demeure un sujet d’actualité. Cette thèse contribue aux discussions actuelles en étudiant plusieurs architectures de marché à mettre en place afin d’assurer la fiabilité du système électrique de la façon la plus efficace.La fiabilité est d’abord étudiée sous sa dimension de court terme, appelée sûreté. Pour garantir un équilibre en temps réel, l’opérateur du système doit s’assurer de disposer d’un niveau suffisant de réserves: c’est l’objectif du modèle de sûreté. Dans cette thèse, les impacts économiques induits par un changement de modèle de sureté pour le système électrique français sont évalués. Une modélisation de type Agent-Based est développée pour simuler les décisions des acteurs sur plusieurs marchés de court terme. Les résultats montrent que le modèle de sureté français actuel conduit à des coûts inférieurs à ceux du modèle alternatif mis en œuvre dans d’autres pays européens. Le maintien du modèle actuel en France apparait donc justifié.La dimension long terme de la fiabilité, à savoir l’adéquation, est ensuite étudiée. Les performances économiques d’un marché de capacité et d’un mécanisme de réserve stratégique, deux solutions conçues pour résoudre le problème d’adéquation, sont comparées. Afin de considérer la nature cyclique des investissements, ces mécanismes sont étudiés d’un point de vue dynamique par l’intermédiaire d’une modélisation de type System Dynamics. Celle-ci simule les décisions d'investissements et de fermetures prises par les acteurs de marché, en considérant leurs comportements imparfaits. Les principaux résultats montrent que le marché de capacité résout la question de l'adéquation à un coût moindre. / Following power market reforms, market design, i.e. the study of new markets to replace efficiently the previous monopoly, becomes central in the economic literature. However, due to several technical characteristics of electricity, this task is complex. A third party is then required to help design these markets in an efficient way and to set the rules under which private decentralized market players will interact. This complexity explains why market design remains a work in progress. This thesis contributes to the current discussions by giving insights on the most efficient market designs to implement to ensure the reliability of power systems.A first focus is made on the short-term dimension of reliability, i.e. the security of power systems. To maintain a balanced system, the system operator has to ensure the availability of a sufficient level of reserves in real time: this is the aim of the security model. In this thesis, a quantitative assessment of the economic impacts that a transition to a different security model would have for the French power system is carried out. An agent-based modelling is developed to simulate the decisions of profit-maximizing players on several short-term markets. Simulations show that the current French security model results in lower costs than the alternative one implemented in several European countries, and should therefore be maintained for the French power system.A second focus is made on the long-term dimension of reliability, i.e. the adequacy. The economic performances of a capacity market and a strategic reserve mechanism, two mechanisms designed to solve the adequacy issue, are compared. In order to capture the cyclical nature of investments, these mechanisms are studied from a dynamic point of view. To this end, a long-term model is developed based on a System Dynamics approach. It simulates the investment and shutdown decisions made by market players considering their imperfect behaviours. Main results show that the capacity market solves the adequacy issue at a lower cost than the strategic reserve mechanism.

This study developed the software named as &ldquo / Physical World&rdquo / which is a virtual laboratory program focusing on Newtonian Physics, which supports two modes called the &ldquo / studying by observation&rdquo / and &ldquo / studying by programming&rdquo / . In &ldquo / studying by observation&rdquo / mode, the motion is calculated due to equations known by the computer. And in &ldquo / studying by programming&rdquo / mode, students write equations of motion and the computer calculates motion due to those equations. A total of six high school second grade students studied force and motion concepts, using Physical World with assistance of one instructor, six hours each. Two of the students studied with &ldquo / studying by observation&rdquo / , two of the students studied with &ldquo / studying by programming&rdquo / , and two of the students studied with use of both of the modes. All students received a test with 10 items chosen from FCI as a pretest and received the same test as a posttest. Students&rsquo / test results were examined to find effects of Physical World&rsquo / s two modes and use of both of the modes over misconceptions about physics. Their actions and responds were examined to find Physical World&rsquo / s effects on scientific thinking for each of the three groups. Four specialists from related fields examined the software and filled evaluation forms and stated feedbacks. From the responds of students during the studies, evidence of positive effect of using the &ldquo / studying by programming&rdquo / mode on scientific thinking was found. And evidence of positive effect of using both modes on misconceptions was found.

Micro-cogeneration is one of the technologies promoted as a response to the global call for the reduction of carbon emissions. Due to its recent application in the residential sector, the implications of its usage have not yet been fully explored, while at the same time, the available simulation tools are not designed for conducting research that focuses on the study of this technology. This thesis develops a virtual prototyping environment, using a dynamic multi-physics simulation tool. The model based procedure in its current form focuses on ICE based micro-CHP systems. In the process of developing the models, new approaches on general system, engine, heat exchanger, and dwelling thermal modelling are being introduced to cater for the special nature of the subject. The developed software is a unique modular simulation tool platform linking a number of independent energy generation systems, and presents a new approach in the study and design of the multi node distributed energy system (DES) with the option of further development into a real-time residential energy management system capable of reducing fuel consumption and CO2 emissions in the domestic sector. In the final chapters, the developed software is used to simulate various internal combustion engine based micro-CHP configurations in order to conclude on the system design characteristics, as well as the conditions, necessary to achieve a high technical, economic and environmental performance in the UK residential sector with the purpose of making micro- CHP a viable alternative to the conventional means of heat & power supply.

A partir de setembro de 1999 até novembro de 2000 estudou-se a várzea da margem direita da planície de inundação do Ribeirão do Feijão, com objetivo de verificação da várzea funcionando como filtro natural na contenção de matéria orgânica utilizando-se para esse estudo, um modelo de simulação desenvolvido com o software Stella. Foram coletados dados climatológicos oriundos de estação climatológica automática (temperatura do ar, umidade relativa, precipitação, radiação solar, velocidade e direção do vento e pressão barométrica), em piezômetros instalados na várzea (em número de 9) e coleta de amostras de água no rio, dados limnológicos: físicos (temperatura da água, turbidez, oxigênio dissolvido, condutividade e profundidade); químicos (fósforo total, fósforo total dissolvido, silicato, nitrogênio total, nitrato, nitrito e amônia), além de dados obtidos pelo estudo da literatura e trabalhos próximos da área de estudo já publicados. A partir do estudo da inter-relação dos processos existentes na várzea de inundação do Ribeirão do Feijão, elaborou-se modelo de simulação. As conclusões que se obtiveram indicam bom comportamento do modelo de simulação e, também, que estudos em escala de tempo mais reduzida sejam utilizados em trabalhos futuros para estudos de várzeas. Outra conclusão refere-se ao funcionamento da várzea como filtro natural, onde houve armazenamento de carbono (matéria orgânica). Constatou-se grande amplitude da variação diária da altura da lâmina d\'água devido à evapotranspiração. Recomenda-se a preservação desse rio porque 40% da água de superfície que abastece a cidade de São Carlos é oriunda desse manancial. / From September 1999 up to November 2000 a wetland of the right margin of Feijão river floodplain was studied with the objective to verify its activity as an natural filter to retain organic matter making use of a simulation model constructed with the help of the Stella software. Were collected climatological data from an automatic climatological station (air temperature, air moisture, rain, solar radiation, speed and wind direction and atmospheric pressure), from piezometers installed within the wetland (number of 9) and samples collected of river water, limnological data: physical data (water temperature, turbidity, dissolved oxygen, conductivity and depth); chemical data (total phosphorus, total dissolved phosphorus, silicate, total nitrogen, nitrate, nitrite and ammonium), moreover data obtained from literature and papers published of sites near the study area. From the interrelationship of processes occurring within the Feijão river floodplain wetland was constructed the simulation model. The obtained conclusions indicate the good simulation model behavior and show that time scales should be shorter in future wetland studies. Other conclusion refer to wetland conduction as a natural filter where occurred carbon storage (organic matter). Great amplitude of water table diary variation have been verified within the wetland due to evapotranspiration. Is possible to recommend the river preservation because 40% of the surface city supply is from this site.

There is growing recognition of the importance of preserving Canada’s forests. Canada’s 348 million hectares of forest land cover 35% of its land area, representing 9% of the world’s forests and 24% of the world’s boreal forests. As a renewable resource, forests offer significant environmental, economic and recreational benefits and innumerable services contributing to the quality of life. Canada has recently entered an era of increased frequency and severity of natural disasters. Ecosystems and communities especially in western Canada have recently undergone a trend of increasing pressures from natural disturbances. These disturbances include wildfires associated with increased fuel load levels from past fire suppression regimes and a widely spread infestation of the mountain pine beetle in addition to changes in weather patterns. Wildfire activity has reached extreme levels in many of the recent years. This thesis profiles an area of western Canada within the Montane Cordillera covering the Nechako Lakes Electoral District in central British Columbia and assesses its vulnerability to the specific hazard of wildfires caused by natural and man-made sources. The objectives of this research are to review, simulate and assess the impact of various fuel management strategies in a sub-section of the Nechako Lakes Electoral District called the Southside. Values at risk include private property and old growth forest in respectively timber supply areas, provincial parks, woodlots and community forests. Simulation results show that firebreaks are effective in significantly reducing the area burned in different parts of the landscape. The performance of different strategies shows large variation. Although this has not been investigated further, such variation has likely been caused by topographic aspects and the positioning of firebreaks in the landscape in relation to climatic parameters. These results can therefore not be extrapolated beyond the simulated area, but do give an indication of the performance variation that may be expected when similar firebreaks are applied elsewhere. The results also show that model performance of all firebreak strategies is heavily and fairly consistently influenced by weather stream parameters. Sensitivity analyses of weather stream parameters show that although the reduction in total area burned varies, the ranking between strategies in their overall performance is consistent regardless of the weather pattern. Combined dry, warm and windy weather conditions lead to a 3.44-fold increase in total area burned as compared to the scenario with average weather conditions. In favourable weather conditions represented by wet, cold and nearly windless conditions, the model shows an 85% reduction in total burned area as compared to the average scenario. These results illustrate the significant impact of uncontrollable variables on the overall result.