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基于用户可信度的Web服务推荐方法 被引量:2
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作者 曹继承 朱小柯 +1 位作者 荆晓远 吴飞 《计算机技术与发展》 2018年第7期117-120,124,共5页
协同过滤是推荐系统中广泛使用的一种推荐技术,但是目前多数基于协同过滤的Web服务推荐算法默认用户反馈数据是可信的,没有考虑到用户反馈数据中会出现的一些范围异常数据和恶意评价数据。如果没有对含有这些干扰数据的用户进行处理,最... 协同过滤是推荐系统中广泛使用的一种推荐技术,但是目前多数基于协同过滤的Web服务推荐算法默认用户反馈数据是可信的,没有考虑到用户反馈数据中会出现的一些范围异常数据和恶意评价数据。如果没有对含有这些干扰数据的用户进行处理,最终的预测结果会受到严重的影响。在分析了用户反馈的服务质量(Qo S)数据的基础上,提出了一种基于用户可信度的Web服务推荐方法。计算用户的可信度并根据可信度对用户进行聚类,选取可信度高的类别中的数据进行协同过滤完成推荐,排除了范围异常数据以及恶意评价数据的干扰,避免了对预测结果的影响,最后使用平均绝对误差和均方根误差评判预测结果。实验结果表明,该方法能有效提高Qo S预测的准确率和Web服务的推荐质量。 展开更多
关键词 协同过滤 Web服务推荐 用户可信度 聚类
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Unusual hydrocarbon waxes detected in Salix oritrepha leaf from Nianbaoyeze Mountains, eastern Qinghai-Tibetan Plateau
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作者 PU Yang cao ji-cheng +2 位作者 JIA Ji-hong SHAO Xiao-hua HAN Yue 《Journal of Mountain Science》 SCIE CSCD 2018年第11期2445-2452,共8页
Plant biomarkers, such as hydrocarbon waxes, are frequently found in various sediments and could be adopted as paleovegetation and paleoclimate indicators. Nevertheless, scarce researches have focused on leaf waxes in... Plant biomarkers, such as hydrocarbon waxes, are frequently found in various sediments and could be adopted as paleovegetation and paleoclimate indicators. Nevertheless, scarce researches have focused on leaf waxes in higher plants of alpine region.Herein, hydrocarbon leaf wax components of Salix oritrepha, which flourish in Nianbaoyeze Mountains in eastern Tibetan Plateau were fully discussed. The n-alkane distribution in leaves ranges from n-C_(21) to nC_(29) with maxima at n-C_(25), which were entirely different with Salix taxa displayed in previous surveys in non-alpine regions. The unusual even carbon nalkenes from n-C_(22:1) to n-C_(30:1), which were thought to appear only in aquatic organisms, were firstly reported in an alpine plant. Additionally, iso-(2-methyl) alkanes, ranging from i-C_(23) to i-C_(29) with maxima at i-C_(25), which have been commonly reported in microorganisms, were also identified in an alpine plant for the first time. Unusual hydrocarbon distribution detected in Salix oritrepha leaf from Nianbaoyeze Mountains is most likely due to the extreme environment in such alpine region. 展开更多
关键词 打蜡 检测 东方 高原 西藏 长叶 极端环境
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