258,825 research outputs found

    How do interactive tabletop systems influence collaboration?

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    This paper examines some aspects of the usefulness of interactive tabletop systems, if and how these impact collaboration. We chose creative problem solving such as brainstorming as an application framework to test several collaborative media: the use of pen-and-paper tools, the ‘‘around-the-table’’ form factor, the digital tabletop interface, the attractiveness of interaction styles. Eighty subjects in total (20 groups of four members) participated in the experiments. The evaluation criteria were task performance, collaboration patterns (especially equity of contributions), and users’ subjective experience. The ‘‘aroundthe-table’’ form factor, which is hypothesized to promote social comparison, increased performance and improved collaboration through an increase of equity. Moreover, the attractiveness of the tabletop device improved subjective experience and increased motivation to engage in the task. However, designing attractiveness seems a highly challenging issue, since overly attractive interfaces may distract users from the task

    An improved approach for automatic process plan generation of complex borings

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    The authors are grateful for funding provided to this project by the French Ministry of Industry, Dassault Aviation, Dassault Systemes, and F. Vernadat for his review and recommendations.The research concerns automated generation of process plans using knowledge formalization and capitalization. Tools allowing designers to deal with issues and specifications of the machining domain are taken into account. The main objective of the current work is to prevent designers from designing solutions that would be expensive and difficult to machine. Among all available solutions to achieve this goal, two are distinguished: the generative approach and the analogy approach. The generative approach is more adapted to generate the machining plans of parts composed of numerous boring operations in interaction. However, generative systems have two major problems: proposed solutions are often too numerous and are only geometrically but not technologically relevant. In order to overcome these drawbacks, two new concepts of feature and three control algorithms are developed. The paper presents the two new features: the Machining Enabled Geometrical Feature (MEGF) and the Machinable Features (MbF). This development is the result of the separation of the geometrical and the technological data contained in one machining feature. The second objective of the paper is to improve the current Process Ascending Generation (PAG) system with control algorithms in order to limit the combinatorial explosion and disable the generation of unusable or not machinable solutions

    Solar energy use for energy savings in dairy processing plants

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    New Zealand is one of the world’s largest producers of dairy products and has a climate with high levels of solar radiation; however, the use of solar energy in the dairy processing industry has received limited attention. An examination of historical records found that the annual peak in New Zealand milk production and processing occurs at a time when solar radiation levels are increasing markedly. An F-Chart analysis was used to simulate the performance of large-area arrays of solar collectors and to determine their suitability for heating and cooling in a dairy processing environment. For the study four types of solar collectors were analysed: glazed flat plates, evacuated tubes, evacuated tubes with CPC reflectors and a building-integrated solar collector under development at the University of Waikato (UoW). It was found that of these technologies, both flat plate and evacuated tubes with CPC reflectors could make useful heating and cooling contributions. Furthermore, the solar fraction was determined mainly by the collector area to storage volume ratio. Finally, it was found that the UoW building-integrated solar collector could make a significant contribution to energy use in dairies and may be an attractive future technology for the industry

    The Port Norfolk Project: Improved Raster Navigation Products From High Resolution Source Data

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    With increasing capabilities in technology, modern hydrographic surveys are comprised of similarly increasing amounts of data, only a minute fraction of which is currently available in the nautical charts produced by the NOAA Office of Coast Survey (OCS). Simultaneously, a tremendous amount of effort goes into the generalization and optimal cartographic representation of the hydrographic data onto raster products, from which the vector products are digitized. Preserving and maintaining a single database of high-resolution vector source data will retain— and make accessible—much more of the hydrographic data collected, alleviate the burden of generalization, and would allow for delivery of high-resolution vector products, as well as a very wide selection of raster products. From high-resolution source data, raster output could be generated at customer specifications. These “user-defined” raster products could be suitably tailored to meet anyone’s needs, regardless if they are a mariner, a scientist, a fisherman, a student, or a casual “common man” customer. The “user-defined” concept will ultimately improve our ability to meet the highly variable needs of our customers. This paper is intended as an exploratory endeavor, specifically, using the Paper Chart Editor component of CARIS HPD to create examples of the kinds of raster products one can create from high-resolution source data, how this process could optimize the current raster chart production workflow within OCS, while also providing a stronger focus on customer service. Finally, the capabilities and lessons learned from the experimentation with HPD will be applied toward the NOAA-wide implementation of Nautical Chart System II (NCSII)

    On the global economic potentials and marginal costs of non-renewable resources and the price of energy commodities

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    A model is presented in this work for simulating endogenously the evolution of the marginal costs of production of energy carriers from non-renewable resources, their consumption, depletion pathways and timescales. Such marginal costs can be used to simulate the long term average price formation of energy commodities. Drawing on previous work where a global database of energy resource economic potentials was constructed, this work uses cost distributions of non-renewable resources in order to evaluate global flows of energy commodities. A mathematical framework is given to calculate endogenous flows of energy resources given an exogenous commodity price path. This framework can be used in reverse in order to calculate an exogenous marginal cost of production of energy carriers given an exogenous carrier demand. Using rigid price inelastic assumptions independent of the economy, these two approaches generate limiting scenarios that depict extreme use of natural resources. This is useful to characterise the current state and possible uses of remaining non-renewable resources such as fossil fuels and natural uranium. The theory is however designed for use within economic or technology models that allow technology substitutions. In this work, it is implemented in the global power sector model FTT:Power. Policy implications are given.Comment: 18 pages, 7 figures, 8 pages of supplementary informatio
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