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历史性数据与知识系统研究进展 被引量:1
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作者 唐常杰 相利民 +1 位作者 熊明 熊岚 《计算机应用》 CSCD 1990年第6期49-54,共6页
本文综述了历史性数据与知识处理系统的研究工作和进展。介绍了项目研究背景,在八十年代初期的模型探索,中期的理论研究,后期的原型实现,以及对未来工作的展望。
关键词 历史性数据 知识系统 时态数据
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历史数据库的前兆依赖及其数学性质 被引量:3
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作者 唐常杰 尹伯文 《中国科学(A辑)》 CSCD 1989年第2期217-224,共8页
本文提出一种新的、易于实现的处理历史性数据的信息系统的数学模型,即带时标的关系数据库+历史规则库=历史数据库。形式化了历史范畴的若干概念,并讨论了一类特殊的历史规则——前兆依赖的性质及其演绎公理系统,并证明了该公理系统的... 本文提出一种新的、易于实现的处理历史性数据的信息系统的数学模型,即带时标的关系数据库+历史规则库=历史数据库。形式化了历史范畴的若干概念,并讨论了一类特殊的历史规则——前兆依赖的性质及其演绎公理系统,并证明了该公理系统的正确性和完备性,证明了历史规则真值集的空虚性问题,无限性问题,等价问题和包含问题都是不可判定的。 展开更多
关键词 数据 历史性数据 信息系统
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QoS Evaluation for Web Service Recommendation 被引量:1
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作者 MA You XIN Xin +3 位作者 WANG Shangguang LI Jinglin SUN Qibo YANG Fangchun 《China Communications》 SCIE CSCD 2015年第4期151-160,共10页
Web service recommendation is one of the most important fi elds of research in the area of service computing. The two core problems of Web service recommendation are the prediction of unknown Qo S property values and ... Web service recommendation is one of the most important fi elds of research in the area of service computing. The two core problems of Web service recommendation are the prediction of unknown Qo S property values and the evaluation of overall Qo S according to user preferences. Aiming to address these two problems and their current challenges, we propose two efficient approaches to solve these problems. First, unknown Qo S property values were predicted by modeling the high-dimensional Qo S data as tensors, by utilizing an important tensor operation, i.e., tensor composition, to predict these Qo S values. Our method, which considers all Qo S dimensions integrally and uniformly, allows us to predict multi-dimensional Qo S values accurately and easily. Second, the overall Qo S was evaluated by proposing an efficient user preference learning method, which learns user preferences based on users' ratings history data, allowing us to obtain user preferences quantifiably and accurately. By solving these two core problems, it became possible to compute a realistic value for the overall Qo S. The experimental results showed our proposed methods to be more efficient than existing methods. 展开更多
关键词 Web service recommendation QoS prediction user preference overall QoSevaluation
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Comparison Between Reconstructions of Global Anthropogenic Land Cover Change over Past Two Millennia 被引量:2
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作者 YAN Mi WANG Zhiyuan +3 位作者 Jed Oliver KAPLAN LIU Jian MIN Shen WANG Sumin 《Chinese Geographical Science》 SCIE CSCD 2013年第2期131-146,共16页
Three global datasets, the History Database of the Global Environment (HYDE), Kaplan and Krurnhardt (KK) and Pongratz of reconstructed anthropogenic land cover change (ALCC) were introduced and compared in this ... Three global datasets, the History Database of the Global Environment (HYDE), Kaplan and Krurnhardt (KK) and Pongratz of reconstructed anthropogenic land cover change (ALCC) were introduced and compared in this paper. The HYDE dataset was recon- structed by Goldewijk and his colleagues at the National institute of Public ttealth and the Environment in Netherland, covering the past 12 000 years. The KK dataset was reconstructed by Kaplan and his colleagues, the Soil-Vegetation-Atmosphere Research Group at the Institute of Environmental Engineering in Switzerland, covering the past 8000 years. The Pongratz dataset was reconstructed by Pon- gratz and her colleagues at the Max Planck Institute for Meteorology in Germany, coveting AD 800-1992. The results show that the reconstructed datasets are quite different from each other due to the different methods used. The three datasets all allocated the historical ALCC according to human population density. The main reason causing the differences among the three datasets lies on the different relationships between population density and land use used in each reconstructed dataset. The KK dataset is better than the other two datasets for two important reasons. First, it used the nonlinear relationship between population density and land use, while the other two used the linear relationship. Second, Kaplan and his colleagues adopted the technological development and intensification parameters and considered the wood harvesting and the long-term fallow area resulted from shifting cultivation, which were neglected in the recon- structions of the other two datasets. Therefore, the KK dataset is more suitable as one of the anthropogenic forcing fields for climate simulation over the past two millennia that is recently concerned by two projects, the National Basic Research Program and the Strategic and Special Frontier Project of Science and Technology of the Chinese Academy of Sciences. 展开更多
关键词 anthropogenic land cover change (ALCC) spatial pattern vegetation type global dataset last two millennia
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Parameter Fitting of Seismic Intensity Attenuation Model in Xinjiang 被引量:1
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作者 Tan Ming Li Shuai +3 位作者 Sun Jing Wang Wei Tang Lihua Wu Chuanyong 《Earthquake Research in China》 2013年第2期261-268,共8页
By using the existing historical earthquake investigation data in Xinjiang,this paper obtained the envelope curves of isoseismal maps of 103 destructive earthquakes occurring from 1716 to 2010 after digitization of th... By using the existing historical earthquake investigation data in Xinjiang,this paper obtained the envelope curves of isoseismal maps of 103 destructive earthquakes occurring from 1716 to 2010 after digitization of the data. The author summarized the seismic intensity attenuation laws in the Xinjiang region with the multiple regression fitting method. The intensity attenuation function of the elliptical model was provided and the fitting results in different periods and areas were compared. Finally, the intensity attenuation relationship in the Xinjiang region was obtained by the method of constraining the start and end of the attenuation curves. 展开更多
关键词 Seismic intensity Attenuation relationship model Xinjiang
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