Data mining is the powerful technique, which can be widely used for discovering the customers’ behaviors as well as customer’s preferences. As a result, it has been widely used in top level companies for evaluating ...Data mining is the powerful technique, which can be widely used for discovering the customers’ behaviors as well as customer’s preferences. As a result, it has been widely used in top level companies for evaluating their Customer Relationship Management (CRM) system today. In this study, a new K-means clustering method proposed to evaluate the cluster customers’ profitability in telecommunication industry in Sri Lanka. Furthermore, RFM model mainly used as an input variable for K-means clustering and distortion curve used to identify optimal number of initial clusters. Based on the results, telecommunication customers’ profitability in Sri Lanka mainly categorized into three levels.展开更多
Density functional theory （DFT） was used to calculate molecular descriptors （properties） for 12 fluoro-quinolone with anti-S.pneumoniae activity. Principal component analysis （PCA） and hierarchical cluster analy...Density functional theory （DFT） was used to calculate molecular descriptors （properties） for 12 fluoro-quinolone with anti-S.pneumoniae activity. Principal component analysis （PCA） and hierarchical cluster analysis （HCA） were employed to reduce dimensionality and investigate in which variables should be more effective for classifying fluoroquinolones according to their degree of an-S.pneumoniae activity. The PCA results showed that the variables ELUMO, Q3, Q5, QA, logP, MR, VOL and △EHL of these compounds were responsible for the anti-S.pneumoniae activity. The HCA results were similar to those obtained with PCA.The methodologies of PCA and HCA provide a reliable rule for classifying new fluoroquinolones with antiS.pneumoniae activity. By using the chemometric results, 6 synthetic compounds were analyzed through the PCA and HCA and two of them are proposed as active molecules with anti-S.pneumoniae, which is consistent with the results of clinic experiments.展开更多
低压台区拓扑信息的准确记录是进行台区线损分析、三相不平衡治理等工作的基础。针对目前拓扑档案排查成本高且效率低的问题,提出一种基于自适应k近邻(adaptive k nearest neighbor,AKNN)异常检验和自适应密度峰值(adaptive density pea...低压台区拓扑信息的准确记录是进行台区线损分析、三相不平衡治理等工作的基础。针对目前拓扑档案排查成本高且效率低的问题,提出一种基于自适应k近邻(adaptive k nearest neighbor,AKNN)异常检验和自适应密度峰值(adaptive density peaks clustering,ADPC)聚类的低压台区拓扑识别方法。该方法利用动态时间弯曲(dynamic time warping,DTW)距离度量低压台区用户间电压序列的相似性,通过AKNN异常检验算法检验并校正异常的用户与变压器之间的关系(简称“户变关系”),在得到正确户变关系的基础上,采用ADPC聚类算法对台区内用户进行相位识别;最后,通过实际台区算例分析验证了该方法不需要人为设置参数,能有效实现低压台区的拓扑识别,具有较高的适用性与准确性。展开更多
快速城镇化背景下,推进土地利用高质量转型是实现区域可持续协同发展的重要路径。该研究基于土地利用主导功能,运用综合指数法、耦合协调度模型和时空地理加权回归模型(geographically and temporally weighted regression,GTWR)等方法...快速城镇化背景下,推进土地利用高质量转型是实现区域可持续协同发展的重要路径。该研究基于土地利用主导功能,运用综合指数法、耦合协调度模型和时空地理加权回归模型(geographically and temporally weighted regression,GTWR)等方法,分析了环鄱阳湖城市群土地利用功能转型的时空演变特征、耦合协调水平及其驱动机制。结果表明:1)2000—2020年,环鄱阳湖城市群土地利用功能指数从0.20上升到0.55,持续优化提升,但总体上处于中低水平,土地利用功能水平表现为阶段性的变化特征;土地利用功能指数逐渐呈现出中西高、东部低的空间格局。2)生产-生活-生态功能及生产-生活功能的协调度指数持续上升,其余耦合度及协调度指数均呈波动发展的趋势,耦合协调度指数呈现中部和西南部高、东北和西北部低的空间分布格局;以低质量转型为主,平均占比约为50%,功能转型质量有所提升,中西部区县的土地利用功能转型质量要明显优于北部和东部区县。3)不同影响因子的驱动作用存在显著的空间差异。人口密度和城镇化水平的正向驱动作用持续增强,二三产业占比的负向驱动作用增强,人均GDP、人均固定资产投资和人均粮食产量的影响力趋于减弱。应根据各区县土地利用功能的转型阶段,实行差别化的发展政策,补齐区县发展短板,提升功能系统间的耦合协调度。研究结果可为提高区域用地效率,促进土地利用多功能协同发展提供参考和决策依据。展开更多
基于Web of Science核心合集数据库和中国知网学术期刊数据库(CNKI),分别从年度发文量、发文作者和机构、高引文章和关键词等角度,采用文献计量法对1980-2022年该领域共208篇中文文献和47篇英文文献进行知识图谱分析,详细阐述了高温大...基于Web of Science核心合集数据库和中国知网学术期刊数据库(CNKI),分别从年度发文量、发文作者和机构、高引文章和关键词等角度,采用文献计量法对1980-2022年该领域共208篇中文文献和47篇英文文献进行知识图谱分析,详细阐述了高温大曲的研究进展和该研究领域未来的发展态势。高温大曲研究是酱香型白酒品质提升的重要方面。近十年来高温大曲的文献研究总体呈现上升趋势。中国学者是发文的主力军,总发文量呈逐年上升趋势,其中WOS数据库发文量增长明显。郎酒集团、茅台集团、江南大学、中国农业大学、中国食品发酵工业研究院等单位是该领域的研究主体。通过本文综合分析,可以为白酒行业相关研究人员了解高温大曲的研究动态和研究方向、开展科研合作与学术交流提供信息帮助。展开更多
文摘Data mining is the powerful technique, which can be widely used for discovering the customers’ behaviors as well as customer’s preferences. As a result, it has been widely used in top level companies for evaluating their Customer Relationship Management (CRM) system today. In this study, a new K-means clustering method proposed to evaluate the cluster customers’ profitability in telecommunication industry in Sri Lanka. Furthermore, RFM model mainly used as an input variable for K-means clustering and distortion curve used to identify optimal number of initial clusters. Based on the results, telecommunication customers’ profitability in Sri Lanka mainly categorized into three levels.
基金This work was supported by National Nature Science Foundation of China and China Academy of Engineering Physics （No. 10376021） Provincial National Science Foundation of He＇nan （No. 2004601107）.
文摘Density functional theory （DFT） was used to calculate molecular descriptors （properties） for 12 fluoro-quinolone with anti-S.pneumoniae activity. Principal component analysis （PCA） and hierarchical cluster analysis （HCA） were employed to reduce dimensionality and investigate in which variables should be more effective for classifying fluoroquinolones according to their degree of an-S.pneumoniae activity. The PCA results showed that the variables ELUMO, Q3, Q5, QA, logP, MR, VOL and △EHL of these compounds were responsible for the anti-S.pneumoniae activity. The HCA results were similar to those obtained with PCA.The methodologies of PCA and HCA provide a reliable rule for classifying new fluoroquinolones with antiS.pneumoniae activity. By using the chemometric results, 6 synthetic compounds were analyzed through the PCA and HCA and two of them are proposed as active molecules with anti-S.pneumoniae, which is consistent with the results of clinic experiments.
文摘低压台区拓扑信息的准确记录是进行台区线损分析、三相不平衡治理等工作的基础。针对目前拓扑档案排查成本高且效率低的问题,提出一种基于自适应k近邻(adaptive k nearest neighbor,AKNN)异常检验和自适应密度峰值(adaptive density peaks clustering,ADPC)聚类的低压台区拓扑识别方法。该方法利用动态时间弯曲(dynamic time warping,DTW)距离度量低压台区用户间电压序列的相似性,通过AKNN异常检验算法检验并校正异常的用户与变压器之间的关系(简称“户变关系”),在得到正确户变关系的基础上,采用ADPC聚类算法对台区内用户进行相位识别;最后,通过实际台区算例分析验证了该方法不需要人为设置参数,能有效实现低压台区的拓扑识别,具有较高的适用性与准确性。
文摘快速城镇化背景下,推进土地利用高质量转型是实现区域可持续协同发展的重要路径。该研究基于土地利用主导功能,运用综合指数法、耦合协调度模型和时空地理加权回归模型(geographically and temporally weighted regression,GTWR)等方法,分析了环鄱阳湖城市群土地利用功能转型的时空演变特征、耦合协调水平及其驱动机制。结果表明:1)2000—2020年,环鄱阳湖城市群土地利用功能指数从0.20上升到0.55,持续优化提升,但总体上处于中低水平,土地利用功能水平表现为阶段性的变化特征;土地利用功能指数逐渐呈现出中西高、东部低的空间格局。2)生产-生活-生态功能及生产-生活功能的协调度指数持续上升,其余耦合度及协调度指数均呈波动发展的趋势,耦合协调度指数呈现中部和西南部高、东北和西北部低的空间分布格局;以低质量转型为主,平均占比约为50%,功能转型质量有所提升,中西部区县的土地利用功能转型质量要明显优于北部和东部区县。3)不同影响因子的驱动作用存在显著的空间差异。人口密度和城镇化水平的正向驱动作用持续增强,二三产业占比的负向驱动作用增强,人均GDP、人均固定资产投资和人均粮食产量的影响力趋于减弱。应根据各区县土地利用功能的转型阶段,实行差别化的发展政策,补齐区县发展短板,提升功能系统间的耦合协调度。研究结果可为提高区域用地效率,促进土地利用多功能协同发展提供参考和决策依据。
文摘基于Web of Science核心合集数据库和中国知网学术期刊数据库(CNKI),分别从年度发文量、发文作者和机构、高引文章和关键词等角度,采用文献计量法对1980-2022年该领域共208篇中文文献和47篇英文文献进行知识图谱分析,详细阐述了高温大曲的研究进展和该研究领域未来的发展态势。高温大曲研究是酱香型白酒品质提升的重要方面。近十年来高温大曲的文献研究总体呈现上升趋势。中国学者是发文的主力军,总发文量呈逐年上升趋势,其中WOS数据库发文量增长明显。郎酒集团、茅台集团、江南大学、中国农业大学、中国食品发酵工业研究院等单位是该领域的研究主体。通过本文综合分析,可以为白酒行业相关研究人员了解高温大曲的研究动态和研究方向、开展科研合作与学术交流提供信息帮助。
