31,132 research outputs found
Impact of trail-side interpretive signs on visitor knowledge
Interpretive signs provide an important tool for enhancing visitor knowledge and understanding during a natural area experience. The Tree Top Walk (TTW) site in Western Australia adopted a minimal approach to interpretive signs to reduce distractions and allow the site to speak for itself. A 1999 pilot visitor survey indicated that many visitors were frustrated at this approach and wanted more signs installed along the walk trails despite the presence of information displays around the visitor kiosk. An interpretive sign trial was carried out in 2001 to assess the impact on visitor knowledge of the natural aspects of the site. While the trail-side interpretive signs provided no additional improvement in visitor knowledge, there appeared to be a positive increase in the perception of the site as providing a learning experience. The addition of trail-side interpretive signs also provided a point of interest for repeat visitors already familiar with the unique experience of the Tree Top Walk
Repeat and first time visitation in an experience specific context: The Valley of the Giants Tree Top Walk.
Communication with the public is a primary consideration in
the design of natural area tourist attractions (Manfredo & Bright,1991; Roggenbuck, 1992; Vogt & Stewart, 1998). In a management context, communication is essential in ensuring a relevant and enjoyable experience on the part of the visiting tourists (Magill, 1995). Communication also serves as an important management aid in reminding visitors of appropriate behaviour while ensuring continued visitor interest in the attraction (Moscardo, 1998; Moscardo & Woods,2001). This paper presents the results of a .survey examining motivations and attitudes of repeat and first time visitors to the Tree Top Walk site in the context of the communication strategy used at the site
A hybrid layout algorithm for sub-quadratic multidimensional scaling
Many clustering and layout techniques have been used for structuring and visualising complex data. This paper is inspired by a number of such contemporary techniques and presents a novel hybrid approach based upon stochastic sampling, interpolation and spring models. We use Chalmers' 1996 O(N/sup 2/) spring model as a benchmark when evaluating our technique, comparing layout quality and run times using data sets of synthetic and real data. Our algorithm runs in O(N/spl radic/N) and executes significantly faster than Chalmers' 1996 algorithm, whilst producing superior layouts. In reducing complexity and run time, we allow the visualisation of data sets of previously infeasible size. Our results indicate that our method is a solid foundation for interactive and visual exploration of data
Coordinating views for data visualisation and algorithmic profiling
A number of researchers have designed visualisation systems that consist of multiple components, through which data and interaction commands flow. Such multistage (hybrid) models can be used to reduce algorithmic complexity, and to open up intermediate stages of algorithms for inspection and steering. In this paper, we present work on aiding the developer and the user of such algorithms through the application of interactive visualisation techniques. We present a set of tools designed to profile the performance of other visualisation components, and provide further functionality for the exploration of high dimensional data sets. Case studies are provided, illustrating the application of the profiling modules to a number of data sets. Through this work we are exploring ways in which techniques traditionally used to prepare for visualisation runs, and to retrospectively analyse them, can find new uses within the context of a multi-component visualisation system
Electricity from photovoltaic solar cells: Flat-Plate Solar Array Project final Report. Volume III: Silicon sheet: wafers and ribbons
The Flat-Plate Solar Array (FSA) Project, funded by the U.S. Government and managed by the Jet Propulsion Laboratory, was formed in 1975 to develop the module/array technology needed to attain widespread terrestrial use of photovoltaics by 1985. To accomplish this, the FSA Project established and managed an Industry, University, and Federal Government Team to perform the needed research and development.
The primary objective of the Silicon Sheet Task of the FSA Project was the development of one or more low-cost technologies for producing silicon sheet suitable for processing into cost-eompetitive solar cells. Silicon sheet refers to high-purity crystalline silicon of size and thickness for fabrication into solar cells.
The Task effort began with state-of-the-art sheet technologies and then solicited and supported any new silicon sheet alternatives that had the potential to achieve the Project goals.
A total of 48 contracts were awarded that covered work in the areas of ingot growth and casting, wafering, ribbon growth, other sheet technologies, and programs of supportive research. Periodic reviews of each sheet technology were held, assessing the technical progress and the long-range potential. Technologies that failed to achieve their promise, or seemed to have lower probabilities for success in comparison with others, were dropped. A series of workshops was initiated to assess the state of the art, to provide insights into problems remaining to be addressed, and to support technology transfer.
The Task made and fostered significant improvements in silicon sheet including processing of both ingot and ribbon technologies. An additional important outcome was the vastly improved understanding of the characteristics associated with high-quality sheet, and the control of the parameters required for higher efficiency solar cells. Although significant sheet cost reductions were made, the technology advancements required to meet the Task cost goals were not achieved.
This FSA Final Report (JPL Publication 86-31, 5101-289, DOE/JPL 1012-125, October 1986) is composed of eight volumes, consisting of an Executive Summary and seven technology reports:
Volume I: Executive Summary.
Volume II: Silicon Material.
Volume III: Silicon Sheet: Wafers and Ribbons
Volume IV: High-Efficiency Solar Celis.
Volume V: Process Development.
Volume VI: Engineering Sciences and Reliability.
Volume VII: Module Encapsulation.
Volume VIII: Project Analysis and Integration.
Two supplemental reports included in the final report package are:
FSA Project: 10 Years of Progress, JPL Document 400-279. 5101-279, October 1985.
Summary of FSA Project Documentation: Abstracts of Published Documents, 1975 to 1986, JPL Publication 82-79 (Revision 1),5101-221, DOE/JPL-1 012-76, September 1986
What do we need for robust and quantitative health impact assessment?
Health impact assessment (HIA) aims to make the health consequences of decisions explicit. Decision-makers need to know that the conclusions of HIA are robust. Quantified estimates of potential health impacts may be more influential but there are a number of concerns. First, not everything that can be quantified is important. Second, not everything that is being quantified at present should be, if this cannot be done robustly. Finally, not everything that is important can be quantified; rigorous qualitative HIA will still be needed for a thorough assessment. This paper presents the first published attempt to provide practical guidance on what is required to perform robust, quantitative HIA. Initial steps include profiling the affected populations, obtaining evidence from for postulated impacts, and determining how differences in subgoups' exposures and suscepibilities affect impacts. Using epidemiological evidence for HIA is different from carrying out a new study. Key steps in quantifying impacts are mapping the causal pathway, selecting appropriate outcome measures and selecting or developing a statistical model. Evidence from different sources is needed. For many health impacts, evidence of an effect may be scarce and estimates of the size and nature of the relationship may be inadequate. Assumptions and uncertainties must therefore be explicit. Modelled data can sometimes be tested against empirical data but sensitivity analyses are crucial. When scientific problems occur, discontinuing the study is not an option, as HIA is usually intended to inform real decisions. Both qualitative and quantitative elements of HIA must be performed robustly to be of value
Energy requirement for the production of silicon solar arrays
An assessment of potential changes and alternative technologies which could impact the photovoltaic manufacturing process is presented. Topics discussed include: a multiple wire saw, ribbon growth techniques, silicon casting, and a computer model for a large-scale solar power plant. Emphasis is placed on reducing the energy demands of the manufacturing process
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