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81.
基于谱修正方法的非高斯风场模拟 总被引:1,自引:0,他引:1
为克服基于H erm ite谱修正方法的缺点,减少该方法中计算H erm ite多项式系数所需耗费的大量机时,提出了一种模拟非高斯风压场的新方法,采用非高斯累积分布函数(CDF)映射技术来代替基于H erm ite的概率密度函数(PDF)修正。选择任意边缘PDF模型作为概率目标模型,采用目标功率谱密度(PSD)作为样本函数,通过迭代修正该样本函数,使其收敛于目标概率密度函数和目标功率谱密度。将该方法应用于实际结构的非高斯风场模拟,模拟结果与目标谱符合良好,表明本文方法模拟非高斯风场具有较高的精确度和计算效率。 相似文献
82.
S. V. Srinivas 《Singapore journal of tropical geography》2008,29(1):87-100
This paper looks at how the city of Hyderabad, the capital of the south Indian state of Andhra Pradesh and production centre of the Telugu film industry, has been represented in recent popular cinema. It outlines the history of a new mode of representing the city in Telugu cinema and argues that its significance lies in the tendency to delocalize the city. Criminalization of the city's older inhabitants, who are marked by either religion (Islam) or their 'non-standard' dialect of Telugu, often accompanies this move. In the process, any claims that they might have on the city are delegitimized. Okkadu, a major commercial hit, restaged the country versus city dichotomy and the antagonisms complicated by cultural and political tensions between the three constituent regions of Andhra Pradesh. This film follows the late 1990s trend in the film industry to recreate entire cityscapes within the studio, ensuring that location shooting in busy city streets and neighbourhoods merely returns us to the grandeur of lavish and 'realistic' studio sets. It reconstructs Hyderabad's most recognizable monument, the 400-year-old Charminar, in addition to its obviously imaginary residential neighbourhood. This paper looks at how and why the city of Hyderabad, especially its older parts, for which Charminar is a metonym, is rendered into a fantasy space in the film. 相似文献
83.
《Geoforum》2017
The Internet and the representation of space therein are almost omnipresent in society and everyday life. Peer-produced geographic data is gaining a particular importance through increasingly available digital tools and techniques that shape the perception of space in the internet, such as flickr, OpenStreetMap or Wikipedia. However, few studies focused on how space is represented, and by whom it is described. We hypothesize that the alleged opening up of geographic information and the assumed benefits for every individual and society through the occurrence of ‘easy-to-use-mapping-tools’ was premature. To explore these assumptions, a comparative study of the flickr worldmap was undertaken and roughly 6.8 million metadatasets of geocoded photos in France, and roughly 50,000 metadatasets in Afghanistan were downloaded and the metadata was analyzed. Our results indicate that photos geocoded in France show a large diversity of motives, while photos geocoded in Afghanistan are mostly limited to content containing warfare when they are up loaded in English. The content of the photo and therefore the representation of space strongly depend on who uploaded the photo, particularly in Afghanistan. We can show that the representation of space on the internet, for the case of flickr, is strongly dominated by perceptions of Western societies and individuals. We therefore confirm our hypothesis that the supposed opening up of geographic information systems through ‘easy-to-use-mapping-tools’ and their democratization thereof was premature. Moreover, we highlight the importance of understanding who contributes online content to be able to evaluate peer-produced data, its value, and its possible applications to avoid reproducing biases. 相似文献
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85.
PEI Xiandeng KONG Lingwang ZHU Yuanhong HUANG Hao 《地球空间信息科学学报》2005,8(4):306-310
IntroductionIn color reproduction and communication, met-amer exists inherently when the conventionalcondition matching used. Therefore , the colordifference introduced makes the accuracy of colorrepresentation be lowered.In order to eli minatemetamer CIE developed the scheme so-calledspectra matching in Publication 15 .2 and speci-fied that using band-pass filters with 5 nminter-val to sample and then reconstruct the originalcolor signal ,thus the color difference will disap-pear[1].Spectra… 相似文献
86.
SHAZongyao BIANFuling 《地球空间信息科学学报》2005,8(1):57-63
This paper introduces some definitions and defines a set of calculating indexes to facilitate the research, and then presents an algorithm to complete the spatial clustering result comparison between different clustering themes. The research shows that some valuable spatial correlation patterns can be further found from the clustering result comparison with multi-themes, based on traditional spatial clustering as the first step. Those patterns can tell us what relations those themes have, and thus will help us have a deeper understanding of the studied spatial entities. An example is also given to demonstrate the principle and process of the method. 相似文献
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89.
D. Sheeren S. Mustière J.‐D. Zucker 《International journal of geographical information science》2013,27(8):961-992
When different spatial databases are combined, an important issue is the identification of inconsistencies between data. Quite often, representations of the same geographical entities in databases are different and reflect different points of view. In order to fully take advantage of these differences when object instances are associated, a key issue is to determine whether the differences are normal, i.e. explained by the database specifications, or if they are due to erroneous or outdated data in one database. In this paper, we propose a knowledge‐based approach to partially automate the consistency assessment between multiple representations of data. The inconsistency detection is viewed as a knowledge‐acquisition problem, the source of knowledge being the data. The consistency assessment is carried out by applying a proposed method called MECO. This method is itself parameterized by some domain knowledge obtained from a second method called MACO. MACO supports two approaches (direct or indirect) to perform the knowledge acquisition using data‐mining techniques. In particular, a supervised learning approach is defined to automate the knowledge acquisition so as to drastically reduce the human‐domain expert's work. Thanks to this approach, the knowledge‐acquisition process is sped up and less expert‐dependent. Training examples are obtained automatically upon completion of the spatial data matching. Knowledge extraction from data following this bottom‐up approach is particularly useful, since the database specifications are generally complex, difficult to analyse, and manually encoded. Such a data‐driven process also sheds some light on the gap between textual specifications and those actually used to produce the data. The methodology is illustrated and experimentally validated by comparing geometrical representations and attribute values of different vector spatial databases. The advantages and limits of such partially automatic approaches are discussed, and some future works are suggested. 相似文献
90.