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991.
白光散斑法——一种较新的用于力学实验分析的方法,从其发展历程出发,简述其在40多年里的发展历史和其目前在中国国内的发展研究现状,并就其基本原理,位移信息提取的两种方法即逐点分析法和全场分析法,做了简要叙述.简单的介绍了白光散斑法的实际测量过程,并简要总结其自身独特的优势、适用的领域和其今后大体发展的趋势.图1,参27. 相似文献
992.
This paper presents a Business Recovery Assessment Framework (BRAF) to help researchers and practitioners design robust, repeatable, and comparable studies of business recovery in various post‐disruption contexts. Studies assessing business recovery without adequately considering the research aims, recovery definitions, and indicators can produce misleading findings. The BRAF is composed of a series of steps that guide the decisions that researchers need to make to ensure: (i) that recovery is indeed being measured; (ii) that the indicators of recovery that are selected align with the objectives of the study and the definition of recovery; and, where necessary, (iii) that appropriate comparative control variables are in place. The paper draws on a large dataset of business surveys collected following the earthquakes in Canterbury, New Zealand, on 4 September 2010 and 22 February 2011 to demonstrate the varied conclusions that different recovery indicators can produce and to justify the need for a systematic approach to business recovery assessments. 相似文献
993.
Sensitivity analysis of the two dimensional application of the Generic Ecological Model (GEM) to algal bloom prediction in the North Sea 总被引:2,自引:0,他引:2
Harmful algae can cause damage to co-existing organisms, tourism and farmers. Accurate predictions of algal future composition and abundance as well as when and where algal blooms may occur could help early warning and mitigating. The Generic Ecological Model is an instrument that can be applied to any water system (fresh, transitional or coastal) to calculate the primary production, chlorophyll-a concentration and phytoplankton species composition. It consists of physical, chemical and ecological model components which are coupled together to build one generic and flexible modelling tool. In this paper the model has been analyzed to assess sensitivity of the simulated chlorophyll-a concentration to a subset of ecologically significant input factors. Only a small number of approaches could be considered as suitable for several reasons including the model complexity, engagement of numerous interacting parameters and relatively long time of a single simulation. Thus, sensitivity analysis has been carried out with the use of the Morris method and later enriched by the computation of the correlation ratios of the selected parameters on the model response at more than a few locations in the modelled area. The obtained results are in agreement with expert knowledge of the ecological processes in the North Sea and correspond well with local characteristics. 相似文献
994.
Understanding how data uncertainty influences ecosystem analysis is critical as we move toward ecosystem-based management. Here, we investigate how 18 Ecological Network Analysis (ENA) indicators that characterize ecosystem growth, development, and condition are affected by uncertainty in an ecosystem model of Lake Sidney Lanier (USA). We applied ENA to 122 plausible parameterizations of the ecosystem developed by Borrett and Osidele (2007, Ecological Modelling 200, 371-387), and then used the coefficient of variation (CV) to compare system indicator variability. We considered Total System Throughput (TST) as a measure of the underlying model uncertainty and tested three hypotheses. First, we hypothesized that non-ratio indicators whose calculation includes the TST would be at least as variable as TST if not more variable. Second, we postulated that indicators calculated as ratios, with TST in the numerator and denominator would tend to be less variable than TST because its influence will cancel. Last, we expected the Average Mutual Information (AMI) to be less variable than TST because it is a bounded function. Our work shows that the 18 indicators grouped into four categories. The first group has significantly larger CVs than the CV for TST. In this group, model uncertainty is amplified rendering these three indicators less useful. The second group of four indicators shows no significant difference in variability with respect to TST. Finally, there are two groups whose CV values are significantly lower than that for TST. The least variable group includes the ratio-based indicators and Average Mutual Information. Due to their low variability, we conclude that these indicators are the most robust to the parameter uncertainty and most useful for ecosystem assessment and comparative ecosystem analysis. In summary, this work suggests that we can be as certain, or more certain, in most of the selected ENA indicators as we are in the parameters of the model analyzed. 相似文献
995.
Structural modifications to landscapes affect the ability of organisms to access different habitat patches. There exist, however, very few general methods by which to relate modifications to expectations of effects, and even fewer that enable understanding of how multiple modifications may interact. In the absence of any guiding principles, ecologists have assumed that interactions will result in complex landscape-scale effects. One way of understanding such effects is through rendering a landscape as a graph or network, among the simplest of which are dendritic networks typified by stream systems. Yet even for stream networks, there are no known general principles concerning the nature of interactions between multiple modifications. We developed a model to describe the ability of fish to access and use different habitat patches within dendritic networks. We used mathematical and numerical analyses of the model to investigate how the habitat value of a network is affected by changes in connectivity and habitat quality, and then to examine interactions between multiple modifications. Rather than showing complex interactions, our analytic and simulation-based results show that the combined effect of multiple modifications approximately equals the sum of individually predicted effects. Dendritic networks thus appear to respond far more simply to multiple modifications than has previously been assumed. These results have implications for stream management planning, and offer a firm foundation from which to better understand population processes within dendritic networks. 相似文献
996.
基于SCI发文的中国生态学研究态势文献计量分析 总被引:1,自引:0,他引:1
采用文献计量学的方法,基于《科学引文索引》数据库近十年的检索结果,定量分析中国生态学领域发文的主题、时间、作者、机构、合作国家、被引频次、期刊分布等数据,系统分析中国生态学领域近十年的研究发展态势、研究热点、研究投入主体、国际合作和研究水平等趋势和特征。基于检索得到的3316篇SCI论文数据,研究认为:我国生态学领域的研究发展迅速。研究的热点主要是分子标记、气候变化、生物多样性、土地利用、分类学、物种、草原、荒漠化、模型、多态性等方面。研究主题的关联性随时间有增加的趋势。588个第一作者发文机构中,中国科学院发文量最高,大学近年的研究发展迅猛。生态学领域篇均作者人数是2.2人。国际合作的主要国家是美国。我国生态学研究的SCI发文篇均被引频次为6。第一作者机构为中国机构的论文被引用情况逊于外国机构。中国生态学领域研究最重要的发文期刊是ECOLOGICAL MODELLING和JOURNAL OF ARID ENVIRONMENTS。 相似文献
997.
《Environmental Communication: A Journal of Nature and Culture》2013,7(2):151-168
In 2008, we published a journal paper arguing that while scholarly work on media representations of environmental issues had made substantial progress in textual analysis, there had been much less work on visual representations. This special edition has a number of aims in this respect. It seeks to mark out where there has been progress since 2008, and the papers in this collection represent some of the fresh and exciting high quality scholarly work now emerging on an expanding number of topics and using different methods. We argue that we need to think more openly about what we mean by “the visual.” We begin by placing research into visual representations of the environment into the wider trajectory of visual studies research. We then proceed to review key trends in visual environmental communication research and to delineate core dimensions, contexts and sites of visual analysis. 相似文献
998.
《Environmental Communication: A Journal of Nature and Culture》2013,7(7):864-878
ABSTRACTTo understand haze-related online communication in Southeast Asia, this exploratory study took a mixed method approach to conduct web analysis of online communication during haze crisis in Singapore, followed by textual analysis of traditional and new media content during peak days. First, web analytics showed that Singapore’s haze online communication occurred mostly on the Twitter platform with primary negative sentiments. Next, textual analysis results found that majority of traditional media-affiliated news provided informative haze reports and centered on positive measurements taken by government and authorities, similar to Public Information Model for crisis management. In comparison, haze-related new media content had diverse topics reflecting laymen’s viewpoints with critical tones and negative sentiments. News portals and blogs used two-way asymmetrical and symmetrical model for crisis management, respectively. Additionally, Social Cognitive Theory’s media diversity perspectives were applied to understand people’s media choices among traditional and new media during natural crisis with environmental influences. 相似文献
999.
《International Journal of Sustainable Engineering》2013,6(2):132-141
Following a brief introduction about the need for businesses to respond to climate change, this paper considers the development of the phrase ‘carbon footprint’. Widely used definitions are considered before the authors offer their own interpretation of how the term should be used. The paper focuses on the contribution small and medium sized enterprises (SMEs) make to the economy and their level of influence in stimulating change within organisations. The experience of an outreach team from the Engineering Department of a UK university is used which draws on the experience of delivering regional economic growth projects funded principally through the European Regional Development Fund. Case studies are used including the development of bespoke carbon footprints for SMEs from an initiative delivered by the outreach team. Limitations of current carbon footprints are identified based on this higher education‐industry knowledge exchange mechanism around three main themes of scope, the assessment method and conversion factors. Evidence and discussions are presented that conclude with the presentation of some solutions based on the work undertaken with SMEs and a discussion on the merits of the two principally used methodologies: life‐cycle analysis and economic input–output assessment. 相似文献
1000.
《International Journal of Sustainable Engineering》2013,6(5):341-348
ABSTRACTIn the present study, construction procedure and performance assessment of expanded polystyrene EPS-geofoam layer, which is utilized in the repair and rehabilitation of road work, is demonstrated. EPS geo-foam application was suggested after observing excessive settlement and distress of approach roads near Cross drainage (C-D) works constructed on bypass road of an important National Highway Project in India. EPS-geofoam was used as an alternative to earth backfill in approaches of newly constructed culvert on the same bypass road on one side of the C-D work and, for comparison purpose; the other side of the C-D work was retained with existing earth backfill. EPS-Geofoam was convenient to handle, easy to place and executed effeciently in terms of machineries and man power. Also, after 6 months of observation, it was noted that Pavement Quality Concrete (PQC) constructed over earthfill material have shown sign of distress and longitudinal cracks were observed due to excessive settlement; on the other hand PQC constructed over EPS-geofoam was intact with no sign of distress. Outcome of the study suggest the use of EPS-geofoam in similar situations as per the proposed guidelines for construction as well as cross-sectional details and design recommended. 相似文献