280,377 research outputs found

    Simulating the influences of groundwater on regional geomorphology using a distributed, dynamic, landscape evolution modelling platform

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    A dynamic landscape evolution modelling platform (CLiDE) is presented that allows a variety of Earth system interactions to be explored under differing environmental forcing factors. Representation of distributed surface and subsurface hydrology within CLiDE is suited to simulation at sub-annual to centennial time-scales. In this study the hydrological components of CLiDE are evaluated against analytical solutions and recorded datasets. The impact of differing groundwater regimes on sediment discharge is examined for a simple, idealised catchment, Sediment discharge is found to be a function of the evolving catchment morphology. Application of CLiDE to the upper Eden Valley catchment, UK, suggests the addition of baseflow-return from groundwater into the fluvial system modifies the total catchment sediment discharge and the spatio-temporal distribution of sediment fluxes during storm events. The occurrence of a storm following a period of appreciable antecedent rainfall is found to increase simulated sediment fluxes

    Sustainable Design and Building Information Modelling: Case Study of Energy Plus House, Hieron's Wood, Derbyshire UK

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    In this paper the method for sustainable design analysis (SDA) integration with building information modelling (BIM) is explored, through the prism of a complex case study based research. BIM model federation and integration challenges are reported, including issues with combining geometry and managing attribute data. The research defines SDA as rapid and quantifiable analysis of multitude of sustainable alternatives and ‘what if’ questions posed by a design team during the early stages of the project, when the benefits of correct decisions can significantly exceed the actual investment required. The SDA concept and BIM integration findings are explained from conceptualisation to calculation stage, emphasising the importance of an iterative over a linear approach. The research approach adopted has led to more informed sustainable solutions at earlier stages of project development, with a generally lower level of development (LOD) and computational/modelling effort required

    A novel haptic model and environment for maxillofacial surgical operation planning and manipulation

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    This paper presents a practical method and a new haptic model to support manipulations of bones and their segments during the planning of a surgical operation in a virtual environment using a haptic interface. To perform an effective dental surgery it is important to have all the operation related information of the patient available beforehand in order to plan the operation and avoid any complications. A haptic interface with a virtual and accurate patient model to support the planning of bone cuts is therefore critical, useful and necessary for the surgeons. The system proposed uses DICOM images taken from a digital tomography scanner and creates a mesh model of the filtered skull, from which the jaw bone can be isolated for further use. A novel solution for cutting the bones has been developed and it uses the haptic tool to determine and define the bone-cutting plane in the bone, and this new approach creates three new meshes of the original model. Using this approach the computational power is optimized and a real time feedback can be achieved during all bone manipulations. During the movement of the mesh cutting, a novel friction profile is predefined in the haptical system to simulate the force feedback feel of different densities in the bone

    Simulation modelling: Educational development roles for learning technologists

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    Simulation modelling was in the mainstream of CAL development in the 1980s when the late David Squires introduced this author to the Dynamic Modelling System. Since those early days, it seems that simulation modelling has drifted into a learning technology backwater to become a member of Laurillard's underutilized, ‘adaptive and productive’ media. Referring to her Conversational Framework, Laurillard constructs a pedagogic case for modelling as a productive student activity but provides few references to current practice and available resources. This paper seeks to complement her account by highlighting the pioneering initiatives of the Computers in the Curriculum Project and more recent developments in systems modelling within geographic and business education. The latter include improvements to system dynamics modelling programs such as STELLA®, the publication of introductory textbooks, and the emergence of online resources. The paper indicates several ways in which modelling activities may be approached and identifies some educational development roles for learning technologists. The paper concludes by advocating simulation modelling as an exemplary use of learning technologies ‐ one that realizes their creative‐transformative potential

    Modelling manure NPK flows in organic farming systems to minimise nitrate leaching, ammonia volatilization and nitrous oxide emissions (OF0197)

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    Manure is an important source of organic matter and nutrients in organic farming systems, principally nitrogen (N), phosphorus (P) and potassium (K). Careful management is required during storage, handling and land-spreading to (a) ensure the most efficient use of the nutrients in the farming system and (b) to limit emissions of nitrate (NO3), ammonia (NH3), nitrous oxide (N2O), methane (CH4) and P to the wider environment. With a likely increase in the organically farmed area, information is needed on best practices for manure management in organic systems to minimise the environmental impacts of these systems. The aim was that software would calculate NPK fluxes associated with each aspect of the livestock system, and provide options to explore the impact of management change at key stages in the manure management process. The end point was to be a working prototype model/decision support system (DSS), which we could be demonstrated to a group of organic farmers and used for discussion of the NPK flows in their systems. Most of the effort in this short-term project was spent on three aspects: 1. Developing databases and the underlying model calculations. 2. Developing the software for the prototype system. 3. Limited validation of the output. The two main challenges in the project were (a) allowing a quick and easy representation of the manure management system, which is often complex and (b) being able to represent complex interactions, simply but robustly. The Manure Model (MANMOD) DSS was developed to allow an iconographic-based model representation of individual farm manure management systems to be readily constructed from a library of system components using a 'drag and drop' operation. This allows the user to construct a diagram of connecting components or ‘nodes’ (e.g. manure source, housing system, storage system) which direct and limit the flow pathway of nutrients through the farming system. Each component or node represents a key stage of the system. Once the system has been constructed, pressing the calculation button calculates the following variates for each component of the system: output (i.e. the amounts of N, P and K that will be transferred from that component of the system to the next); balance (i.e. the amount residing in that component of the system); losses (gaseous and ‘leachate’). Workshops were held at the start and end of the project. The following observations were made as a result of this exercise: - The approach is a relatively quick and simple way of constructing manure management systems. However, it is still quite complex, given the complexity of many management systems. - It may be that it is a better tool for advisers so that they can use it for several clients and become more familiar with the tool, compared with a farmer who might use it as a one-off during planning. - Even at its simplest, some detailed information is required – and in units that the farmer may not be familiar with. For example, washdown volume for the hardstanding, amount of straw (kg/animal/month), etc. However, this is not really a reason for not pursuing this information if it will provide an improvement in management. - One value is the option to scenario test. However, this is reliant on the model being sufficiently refined to be able to fairly represent the changes in response to the system. The aim of the project was to produce a prototype system. We have done this, but because of the complexity of the systems that we are trying to represent, we recognise that much more detailed validation of the model is required before it can be disseminated. There are now several Defra-funded studies that could be used in the next phase of the work. (A more detailed summary is available at the start of the main report

    Integration of environmental data in BIM tool & linked building data

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    Environmental assessment is a critical need to ensure building sustainability. In order to enhance the sustainability of building, involved actors should be able to access and share not only information about the building but also data about products and especially their environmental assessment. Among several approaches that have been proposed to achieve that, semantic web technologies stand out from the crowd by their capabilities to share data and enhance interoperability in between the most heterogeneous systems. This paper presents the implementation of a method in which semantic web technologies and particularly Linked Data have been combined with Building Information Modelling (BIM) tools to foster building sustainability by introducing products with their environmental assessment in building data during the modelling phase. Based on Linked Building Data (LBD) vocabularies and environmental data, several ontologies have been generated in order to make both of them available as Resource Description Framework (RDF) graphs. A database access plugin has been developed and installed in a BIM tool. In that way, the LBD generated from the BIM tool contains, for each product a reference to its environmental assessment which is contained in a triplestore
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