179,804 research outputs found

    Discrete Event Simulation Implemented in a Virtual Environment

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    Virtual reality (VR) technology provides a human-computer interface that allows participants to interact naturally with digital objects which are represented as three-dimensional images that occupy positions in a three-dimensional world. Related to problems of engineering design and manufacturing, this new technology offers engineers the ability to work with computer models in a three-dimensional, immersive environment. This paper describes a virtual reality application where the results of a discrete event simulation of a manufacturing cell are integrated with a virtual model of the cell to produce a virtual environment. The program described in this paper, the VRFactory, combines results from a commercial discrete event simulation program, SLAM II, with a virtual environment. This allows the user to investigate, using three-dimensional computer models, how various changes to the manufacturing cell affect part production. This investigation is performed while immersed in a computer-generated three-dimensional representation of the cell. Existing discrete event programming software allows only two-dimensional views of the factory as the parts progress through the simulation. Parts are shown only as primitive geometric shapes on the computer monitor and instantaneously move from one station to the next. The virtual environment implementation of the SLAM II results allows users to experience the simulation in a fully immersive three-dimensional digital environment. The virtual environment used here is a CAVEâ„¢-like projection screen-based facility called the C2, which is located at Iowa State University. This paper describes the creation of the VR model of the manufacturing cell, the animation of the environment and the implementation of the results of the discrete event simulation

    The need for improved management of the subsurface

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    The subsurface is used intensively to support economic stability and growth. Human interaction with the shallow subsurface ranges from exploitation of resources, accommodation of utilities, harnessing of energy (ground source heat pumps) and storage of waste. Current practice of managing these shallow subsurface zones is far from ideal. Many subsurface interventions are preceded by feasibility studies, predictive models or investigative measures to mitigate risks or predict the impacts of the work. However, the complex interactions between the anthropogenic structures and natural processes mean that a holistic impact assessment is often not achievable. By integrating these subsurface infrastructures within three dimensional framework models, a comprehensive assessment of the potential hazards in these shallow subsurface environments may be made. Some Geological Survey Organizations (GSOs) are currently developing subsurface management systems that will aid decision making in the shallow subsurface [1]. The British Geological Survey (BGS) is developing an open Environmental Modeling Platform [2] to provide the data standards and applications to link models, numerical simulations and ultimately socio-economic models so as to generate predictive responses to questions concerning sustainable us of the subsurface

    Multi-dimensional modelling for the national mapping agency: a discussion of initial ideas, considerations, and challenges

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    The Ordnance Survey, the National Mapping Agency (NMA) for Great Britain, has recently begun to research the possible extension of its 2-dimensional geographic information into a multi-dimensional environment. Such a move creates a number of data creation and storage issues which the NMA must consider. Many of these issues are highly relevant to all NMA’s and their customers alike, and are presented and explored here. This paper offers a discussion of initial considerations which NMA’s face in the creation of multi-dimensional datasets. Such issues include assessing which objects should be mapped in 3 dimensions by a National Mapping Agency, what should be sensibly represented dynamically, and whether resolution of multi-dimensional models should change over space. This paper also offers some preliminary suggestions for the optimal creation method for any future enhanced national height model for the Ordnance Survey. This discussion includes examples of problem areas and issues in both the extraction of 3-D data and in the topological reconstruction of such. 3-D feature extraction is not a new problem. However, the degree of automation which may be achieved and the suitability of current techniques for NMA’s remains a largely unchartered research area, which this research aims to tackle. The issues presented in this paper require immediate research, and if solved adequately would mark a cartographic paradigm shift in the communication of geographic information – and could signify the beginning of the way in which NMA’s both present and interact with their customers in the future

    Dimensions of web site credibility and their relation to active trust and behavioural impact

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    This paper discusses two trends that threaten to undermine the effectiveness of online social marketing interventions: growing mistrust and competition. As a solution, this paper examines the relationships between Web site credibility, target audiences’ active trust and behaviour. Using structural equation modelling to evaluate two credibility models, this study concludes that Web site credibility is best considered a three-dimensional construct composed of expertise, trustworthiness and visual appeal, and that trust plays a partial mediating role between Web site credibility and behavioural impacts. The paper examines theoretical implications of conceptualizing Web sites according to a human credibility model, and factoring trust into Internet-based behavioural change interventions. Practical guidelines suggest ways to address these findings when planning online social marketing interventions

    Where creativity comes from: the social spaces of embodied minds

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    This paper explores creative design, social interaction and perception. It proposes that creativity at a social level is not a result of many individuals trying to be creative at a personal level, but occurs naturally in the social interaction between comparatively simple minds embodied in a complex world. Particle swarm algorithms can model group interaction in shared spaces, but design space is not necessarily one pre-defined space of set parameters on which everyone can agree, as individual minds are very different. A computational model is proposed that allows a similar swarm to occur between spaces of different description and even dimensionality. This paper explores creative design, social interaction and perception. It proposes that creativity at a social level is not a result of many individuals trying to be creative at a personal level, but occurs naturally in the social interaction between comparatively simple minds embodied in a complex world. Particle swarm algorithms can model group interaction in shared spaces, but design space is not necessarily one pre-defined space of set parameters on which everyone can agree, as individual minds are very different. A computational model is proposed that allows a similar swarm to occur between spaces of different description and even dimensionality
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