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Comparing of Aviation Network Structure of Mid-south,Northwest and Southwest of China Based on Hierarchical Index Model 被引量:1
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作者 Cheng Xiangjun Yang Fang Xie Li 《Journal of Traffic and Transportation Engineering》 2020年第1期14-19,共6页
In order to compare the aviation network of mid-south,northwest and southwest of China to reveal the structure similarity and difference for providing quantitative evidence to construct regional aviation network and i... In order to compare the aviation network of mid-south,northwest and southwest of China to reveal the structure similarity and difference for providing quantitative evidence to construct regional aviation network and improve its structure,hierarchical index model of regional aviation network was established through dividing the aviation network into layers to research its structure characters.Data matrixes were defined to record the basic state of regional aviation network.Index matrixes were constructed to describe the quantitative features of regional aviation network.On the basis of these indexes,several structure indexes of all layers of aviation network were calculated to show the structure features of aviation network,such as ratio of passenger volume within the region with across the region,share rate of passenger volume among layers,ratio of average number of airline for each airport,ratio of average passenger volume for each airline and ratio of airline rate.According to the statistical data,similar structure of share rate of passenger volume among layers and average passenger volume for each airline in their regional aviation network was found after calculating.But on the side of ratio of passenger volume within the region with across the region,ratio of average number of airlines for each airport and ratio of airline rate were different. 展开更多
关键词 Regional aviation network comparing of structure hierarchical index model index matrix structure index
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Research on Protecting Information Security Based on the Method of Hierarchical Classification in the Era of Big Data 被引量:5
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作者 Guangyong Yang Mengke Yang +1 位作者 Shafaq Salam Jianqiu Zeng 《Journal of Cyber Security》 2019年第1期19-28,共10页
Big data is becoming increasingly important because of the enormous information generation and storage in recent years.It has become a challenge to the data mining technique and management.Based on the characteristics... Big data is becoming increasingly important because of the enormous information generation and storage in recent years.It has become a challenge to the data mining technique and management.Based on the characteristics of geometric explosion of information in the era of big data,this paper studies the possible approaches to balance the maximum value and privacy of information,and disposes the Nine-Cells information matrix,hierarchical classification.Furthermore,the paper uses the rough sets theory to proceed from the two dimensions of value and privacy,establishes information classification method,puts forward the countermeasures for information security.Taking spam messages for example,the massive spam messages can be classified,and then targeted hierarchical management strategy was put forward.This paper proposes personal Information index system,Information management platform and possible solutions to protect information security and utilize information value in the age of big data. 展开更多
关键词 Big data hierarchical classification rough sets information index system
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Local and regional flood frequency analysis based on hierarchical Bayesian model in Dongting Lake Basin,China 被引量:1
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作者 Yun-biao Wu Lian-qing Xue Yuan-hong Liu 《Water Science and Engineering》 EI CAS CSCD 2019年第4期253-262,共10页
This study developed a hierarchical Bayesian(HB)model for local and regional flood frequency analysis in the Dongting Lake Basin,in China.The annual maximum daily flows from 15 streamflow-gauged sites in the study are... This study developed a hierarchical Bayesian(HB)model for local and regional flood frequency analysis in the Dongting Lake Basin,in China.The annual maximum daily flows from 15 streamflow-gauged sites in the study area were analyzed with the HB model.The generalized extreme value(GEV)distribution was selected as the extreme flood distribution,and the GEV distribution location and scale parameters were spatially modeled through a regression approach with the drainage area as a covariate.The Markov chain Monte Carlo(MCMC)method with Gibbs sampling was employed to calculate the posterior distribution in the HB model.The results showed that the proposed HB model provided satisfactory Bayesian credible intervals for flood quantiles,while the traditional delta method could not provide reliable uncertainty estimations for large flood quantiles,due to the fact that the lower confidence bounds tended to decrease as the return periods increased.Furthermore,the HB model for regional analysis allowed for a reduction in the value of some restrictive assumptions in the traditional index flood method,such as the homogeneity region assumption and the scale invariance assumption.The HB model can also provide an uncertainty band of flood quantile prediction at a poorly gauged or ungauged site,but the index flood method with L-moments does not demonstrate this uncertainty directly.Therefore,the HB model is an effective method of implementing the flexible local and regional frequency analysis scheme,and of quantifying the associated predictive uncertainty. 展开更多
关键词 Flood frequency analysis hierarchical Bayesian model index flood method Generalized extreme value distribution Dongting Lake Basin
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Study of a Comprehensive Assessment Method for Coal Mine Safety Based on a Hierarchical Grey Analysis 被引量:26
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作者 LIU Ya-jing MAO Shan-jun +1 位作者 LI Mei YAO Ji-ming 《Journal of China University of Mining and Technology》 EI 2007年第1期6-10,共5页
Coal mine safety is a complex system, which is controlled by a number of interrelated factors and is difficult to estimate. This paper proposes an index system of safety assessment based on correlated factors involved... Coal mine safety is a complex system, which is controlled by a number of interrelated factors and is difficult to estimate. This paper proposes an index system of safety assessment based on correlated factors involved in coal mining and a comprehensive evaluation model that combines the advantages of the AHP and a grey clustering method to guarantee the accuracy and objectivity of weight coefficients. First, we confirmed the weight of every index using the AHP, then did a general safety assessment by means of a grey clustering method. This model analyses the status of mining safety both qualitatively and quantitatively. It keeps management and technical groups informed of the situation of the coal production line in real time, which aids in making correct decisions based on practical safety issues. A case study in the application of the model is presented. The results show that the method is applicable and realistic with regard to the core of a coal mine's safety management. Consequently, the safe production of a mine and the awareness of advanced safe production management is accelerated. 展开更多
关键词 煤矿 安全性 安全事故 灰色分析
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DESIGN OF EXACT REGENERATING HIERARCHICAL CODE FOR DISTRIBUTED STORAGE SYSTEM 被引量:1
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作者 Hao Jie Lu Yanbo +1 位作者 Liu Xinji Xia Shutao 《Journal of Electronics(China)》 2013年第3期290-298,共9页
Erasure code is widely used as the redundancy scheme in distributed storage system. When a storage node fails, the repair process often requires to transfer a large amount of data. Regenerating code and hierarchical c... Erasure code is widely used as the redundancy scheme in distributed storage system. When a storage node fails, the repair process often requires to transfer a large amount of data. Regenerating code and hierarchical code are two classes of codes proposed to reduce the repair bandwidth cost. Regenerating codes reduce the amount of data transferred by each helping node, while hierarchical codes reduce the number of nodes participating in the repair process. In this paper, we propose a "sub-code nesting framework" to combine them together. The resulting regenerating hierarchical code has low repair degree as hierarchical code and lower repair cost than hierarchical code. Our code can achieve exact regeneration of the failed node, and has the additional property of low updating complexity. 展开更多
关键词 Distributed storage Network coding Regenerating code hierarchical code Repair cost CLC index TP302.8
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A Multilevel Secure Relation-Hierarchical Data Model for a Secure DBMS
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作者 朱虹 冯玉才 《Journal of Modern Transportation》 2001年第1期8-16,共9页
A multilevel secure relation hierarchical data model for multilevel secure database is extended from the relation hierarchical data model in single level environment in this paper. Based on the model, an upper lowe... A multilevel secure relation hierarchical data model for multilevel secure database is extended from the relation hierarchical data model in single level environment in this paper. Based on the model, an upper lower layer relationalintegrity is presented after we analyze and eliminate the covert channels caused by the database integrity.Two SQL statements are extended to process polyinstantiation in the multilevel secure environment.The system based on the multilevel secure relation hierarchical data model is capable of integratively storing and manipulating complicated objects ( e.g. , multilevel spatial data) and conventional data ( e.g. , integer, real number and character string) in multilevel secure database. 展开更多
关键词 DATABASES data structure data models secure DBMS covert channels mandatory access control POLYINSTANTIATION hierarchical classification non hierarchical category security level integrity cluster index
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OBH-RSI:Object-Based Hierarchical Classification Using Remote Sensing Indices for Coastal Wetland
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作者 Zhaoyang Lin Jianbu Wang +4 位作者 Wei Li Xiangyang Jiang Wenbo Zhu Yuanqing Ma Andong Wang 《Journal of Beijing Institute of Technology》 EI CAS 2021年第2期159-171,共13页
With the deterioration of the environment,it is imperative to protect coastal wetlands.Using multi-source remote sensing data and object-based hierarchical classification to classify coastal wetlands is an effective m... With the deterioration of the environment,it is imperative to protect coastal wetlands.Using multi-source remote sensing data and object-based hierarchical classification to classify coastal wetlands is an effective method.The object-based hierarchical classification using remote sensing indices(OBH-RSI)for coastal wetland is proposed to achieve fine classification of coastal wetland.First,the original categories are divided into four groups according to the category characteristics.Second,the training and test maps of each group are extracted according to the remote sensing indices.Third,four groups are passed through the classifier in order.Finally,the results of the four groups are combined to get the final classification result map.The experimental results demonstrate that the overall accuracy,average accuracy and kappa coefficient of the proposed strategy are over 94%using the Yellow River Delta dataset. 展开更多
关键词 Yellow River Delta vegetation index object-based hierarchical classification WETLAND multi-source remote sensing
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Structure Evolution of China Aviation Network Based on Hierarchical Model
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作者 Cheng Xiangjun Chen Xumei Li Tao 《Journal of Traffic and Transportation Engineering》 2022年第3期95-103,共9页
The annual passenger volume of airport reflected its passenger transport scale and the role in aviation network.The airports in whole country were divided into three layers:first layer airports,second layer airports a... The annual passenger volume of airport reflected its passenger transport scale and the role in aviation network.The airports in whole country were divided into three layers:first layer airports,second layer airports and third layer airports.The airlines from the first layer airports consisted the first layer aviation network.The airlines from the second layer airports consisted the second layer aviation network.The airlines from the third layer airports consisted the third layer aviation network.The structure and function of different layer aviation network had significant differences.These differences were shown in the number of airlines,average number of airlines of each airport,annual passenger volume of airport and average passenger volume of each airline.National aviation network hierarchical model was constructed to describe the whole country aviation network.The matrix was built to describe the airline number,annual passenger volume,average number of airlines,average passenger volume of each airport and airline rate of aviation network.The index of national aviation network structure was constructed to show the ratio of index between different aviation network layer to describe the aviation network structure.The structure index was built to illustrate the macrostructural features of national aviation network.The statistics data in year 1988,1994,2001,2008 and 2015 of China aviation network were analyzed and basic data matrixes,basic index matrixes and structure index matrixes were calculated.The trend of ratio of corresponding index between the first layer and the second layer showed the change of basic structure of China aviation network.At meantime,the tendency of ratio of corresponding index between the third layer and the second layer also showed the change of basic structure.The trend of network general structure index illustrated that the large scaled new airports and airlines construction had significant influence on the national aviation network structure. 展开更多
关键词 National aviation network structure evolution hierarchical model structure index matrix
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Neighborhood Effects and Political Trust: A Multi-level Analysis of Chinese Rural-to-Urban Migrants’ Trust in County Government
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作者 Chen Zhang 《Management Studies》 2023年第3期105-124,共20页
Massive rural-to-urban migration in China is consequential for political trust: rural-to-urban migrants have been found to hold lower levels of trust in local government than their rural peers who choose to stay in th... Massive rural-to-urban migration in China is consequential for political trust: rural-to-urban migrants have been found to hold lower levels of trust in local government than their rural peers who choose to stay in the countryside (mean 4.92 and 6.34 out of 10, respectively, p < 0.001). This article explores why migrants have a certain level of political trust in their county-level government. Using data of rural-to-urban migrants from the China Family Panel Survey, this study performs a hierarchical linear modeling (HLM) to unpack the multi-level explanatory factors of rural-to-urban migrants’ political trust. Findings show that the individual-level socio-economic characteristics and perceptions of government performance (Level-1), the neighborhood-level characteristics-the physical and social status and environment of neighborhoods (Level-2), and the objective macroeconomic performance of county-level government (Level-3), work together to explain migrants’ trust levels. These results suggest that considering the effects of neighborhood-level factors on rural-to-urban migrants’ political trust merits policy and public management attention in rapidly urbanizing countries. 展开更多
关键词 rural-to-urban migrants multi-level analysis neighborhood effects political trust hierarchical linear modeling China
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基于Donabedian理论的儿童肝移植全周期护理质量指标体系构建 被引量:1
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作者 唐诗 黄明珠 +3 位作者 陆晔峰 刘文卓 王贝贝 王艳 《中国医学科学院学报》 CAS CSCD 北大核心 2024年第1期55-61,共7页
目的初步构建儿童肝移植全周期护理质量指标体系,以期为护理质量监测及管理提供依据。方法以Donabedian“结构-过程-结果”三维质量评价模型为理论框架,采用文献分析、德尔菲法及层次分析法,构建儿童肝移植全周期护理质量指标体系的内... 目的初步构建儿童肝移植全周期护理质量指标体系,以期为护理质量监测及管理提供依据。方法以Donabedian“结构-过程-结果”三维质量评价模型为理论框架,采用文献分析、德尔菲法及层次分析法,构建儿童肝移植全周期护理质量指标体系的内容及指标权重。结果3轮函询问卷的有效回收率均为100%,专家权威系数分别为0.95、0.96、0.98,肯德尔和谐系数分别为0.165、0.209、0.220(P均<0.001)。最终构建的质量指标体系包括一级指标3项、二级指标15项、三级指标67项。结论初步构建儿童肝移植全周期护理质量指标体系,可为儿童肝移植护理质量评价提供参考依据。 展开更多
关键词 儿童肝移植 全周期 护理质量 指标 德尔菲法 层次分析
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省域视角下中国优势学科识别与分析——基于分级评价方法
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作者 赵展一 钟永恒 +2 位作者 刘佳 孙源 李贞贞 《科技管理研究》 2024年第6期64-71,共8页
优势学科是一个相对概念,比较视角可以是国家、省份、机构、学科等。目前评价学科水平主要以基本科学指标数据库(ESI)为依据,但ESI学科分类并不能较好地反映中国的学科发展情况,且ESI及其他一些引文分析法存在时滞性和缺乏省际横向比较... 优势学科是一个相对概念,比较视角可以是国家、省份、机构、学科等。目前评价学科水平主要以基本科学指标数据库(ESI)为依据,但ESI学科分类并不能较好地反映中国的学科发展情况,且ESI及其他一些引文分析法存在时滞性和缺乏省际横向比较的弊端。因此,从省域视角探索建立优势学科识别与分析方法体系,为加快建设具有中国特色的世界一流学科、促进各省份完善学科布局提供参考。以美国科学引文索引(SCI)收录论文为数据源,以SCI期刊分类与中国《研究生教育学科专业目录(2022年)》进行映射得到的77个学科作为依据,建立学科相对优势指数和发展潜力优势指数,并综合考虑省份学科规模和质量水平,利用分级评价的方式识别中国31个省份各自的优势学科和潜力学科。结果显示,中国31个省份的优势学科合计125个、潜力学科合计129个。这与各省份学科发展现状基本吻合,证明所提出方法的可行性。据此,各省份可进一步优化资源配置,强化现有优势,同时对亟需资助的潜力学科、弱势学科给予倾斜,构建合理的学科结构。 展开更多
关键词 优势学科 潜力学科 分级评价 相对优势指数 发展潜力优势指数 中国省域
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锡林郭勒盟大型露天煤矿区地质环境时空演化评价
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作者 何辉 穆文平 +5 位作者 张晓 宋煜冰 吕远洋 武雄 叶宝莹 白中科 《地学前缘》 EI CAS CSCD 北大核心 2024年第3期443-457,共15页
内蒙古锡林郭勒盟大型露天煤矿区经过20多年的开发,产生了一系列矿山地质环境问题,矿区地质环境在一定程度上遭到破坏,因此,开展大型露天煤矿区地质环境时空演化评价可为矿区生态地质环境修复提供参考。本文对锡林郭勒盟3个大型矿区进... 内蒙古锡林郭勒盟大型露天煤矿区经过20多年的开发,产生了一系列矿山地质环境问题,矿区地质环境在一定程度上遭到破坏,因此,开展大型露天煤矿区地质环境时空演化评价可为矿区生态地质环境修复提供参考。本文对锡林郭勒盟3个大型矿区进行地质环境时空演化评价。首先通过现场调查,明确了研究区主要的矿山地质环境问题,包括植被覆盖度下降、土地压占(排土场和工业场地)、地形地貌景观破坏(露天采坑)和含水层破坏等4类;其次利用遥感影像定量获取了2000—2020年之间的矿山地质环境问题信息,并建立了矿山地质环境评价指标体系;然后应用层次分析法确定了矿山地质环境评价指标的权重,并通过基于GIS的影响指数模型对矿山地质环境影响进行了评价和区划,探讨了矿山地质环境时空演化规律。研究结果表明:(1)3个大型矿区植被覆盖度下降区域的面积、排土场压占土地面积和露天采坑破坏地形地貌景观面积随时间不断增加;(2)大型矿区采矿对地质环境的影响划分为无影响区、轻微影响区、一般影响区、较强影响区和强烈影响区5个等级分区;(3)3个大型矿区地质环境时空演化规律基本相同,不同影响区的空间分布特征和面积随时间变化的规律不同。 展开更多
关键词 露天煤矿区 地质环境 植被覆盖度 层次分析法 影响指数模型 时空演化评价
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基于分区层次图的海量高维数据学习索引构建方法
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作者 华悦琳 周晓磊 +2 位作者 范强 王芳潇 严浩 《计算机工程与科学》 CSCD 北大核心 2024年第7期1193-1201,共9页
学习索引是破解海量高维数据近似最近邻搜索问题的关键。然而,现有学习索引技术结果仅局限于单个分区中,且依赖于近邻图的构建。随着数据维度和规模的增长,索引难以对分区边界数据进行精确判断,并且构建时间复杂度增大,可扩展性难以保... 学习索引是破解海量高维数据近似最近邻搜索问题的关键。然而,现有学习索引技术结果仅局限于单个分区中,且依赖于近邻图的构建。随着数据维度和规模的增长,索引难以对分区边界数据进行精确判断,并且构建时间复杂度增大,可扩展性难以保障。针对上述问题,提出了基于分区层次图的学习索引方法PBO-HNSW。该方法对分区边界数据进行重新分配,并行构建分布式图索引结构,从而有效应对近似最近邻搜索问题所面临的挑战。实验结果表明,该方法能够在百万级海量高维数据上实现毫秒级的索引构建。当召回率为0.93时,PBO-HNSW方法构建时间仅为基线方法的36.4%。 展开更多
关键词 近似最近邻搜索 学习索引 层次可导航小世界图 分区学习 索引结构
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基于多时相Sentinel-2A影像的狼毒分布识别
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作者 房家玮 胡念钊 +1 位作者 王怀玉 刘咏梅 《草业科学》 CAS CSCD 北大核心 2024年第2期322-331,共10页
狼毒(Stellera chamaejasme)是近年来青藏高原高寒草地的主要入侵毒杂草之一,及时高效的调查与监测可为狼毒综合防控与退化草地恢复提供重要的技术支持。本研究选取花期前与盛花期的Sentinel-2A多光谱影像,将Google Earth Engine平台去... 狼毒(Stellera chamaejasme)是近年来青藏高原高寒草地的主要入侵毒杂草之一,及时高效的调查与监测可为狼毒综合防控与退化草地恢复提供重要的技术支持。本研究选取花期前与盛花期的Sentinel-2A多光谱影像,将Google Earth Engine平台去云、环境要素掩膜、特征优选和随机森林分类相结合,探讨区域尺度的狼毒遥感识别方法。结果表明,通过狼毒敏感指数计算,以及Spearman秩相关性分析与随机森林重要性排序相结合的二次降维,提取了7项狼毒分类特征并构建了4个特征组合方案。与单时相特征组合相比,多时相特征组合有效提高了狼毒识别精度,其中,基于随机森林模型的6个特征组合方案的分类总精度为84.62%,狼毒分类精度均大于80%,识别效果最佳。本研究显示,影像去云及掩膜预处理能够有效减少分类干扰信息,花期前与盛花期提取的多时相特征组合增强了狼毒群落与其他群落的影像光谱差异,在区域尺度狼毒遥感识别中具有较好的应用潜力。 展开更多
关键词 去云 特征优选 分层掩膜 多时相分析 随机森林 敏感指数 狼毒
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护理研究生科研伦理素养评价指标体系的构建
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作者 孔浩鑫 李明霞 +1 位作者 王雪贝 林树豪 《护理学杂志》 CSCD 北大核心 2024年第12期112-115,共4页
目的构建护理研究生科研伦理素养评价指标体系,为客观评价护理研究生的科研伦理素养提供工具。方法以素质冰山模型为理论基础,基于文献回顾和小组讨论拟订护理研究生科研伦理素养评价指标体系初稿,应用德尔菲法和层次分析法确定最终评... 目的构建护理研究生科研伦理素养评价指标体系,为客观评价护理研究生的科研伦理素养提供工具。方法以素质冰山模型为理论基础,基于文献回顾和小组讨论拟订护理研究生科研伦理素养评价指标体系初稿,应用德尔菲法和层次分析法确定最终评价指标体系和权重。结果2轮函询专家积极系数分别为100%和85.0%,专家权威系数为0.900、0.921,肯德尔和谐系数为0.134、0.189(均P<0.05)。最终形成的护理研究生科研伦理素养评价指标体系,包括2个一级指标(外显科研伦理素养、内隐科研伦理素养)、5个二级指标(科研伦理知识、科研伦理技能、科研伦理能力、科研伦理态度、科研伦理价值观)、31个三级指标。结论构建的护理研究生科研伦理素养评价指标体系科学合理,可作为护理研究生科研伦理素养的评价工具。 展开更多
关键词 护理研究生 护理科研 科研伦理 素养 评价指标体系 素质冰山模型 德尔菲法 层次分析法
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有向图上基于层次树索引的最大cycle truss社区搜索
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作者 宗传玉 张纯鹤 夏秀峰 《计算机应用》 CSCD 北大核心 2024年第1期190-198,共9页
社区搜索旨在从信息网络中找出包含用户查询顶点的高内聚连通子图,cycle truss是一种基于cycle三角形的社区搜索模型,而现有的基于索引的cycle truss社区搜索方法存在索引空间大、搜索效率低、社区内聚性低的缺点。为了解决这一问题,提... 社区搜索旨在从信息网络中找出包含用户查询顶点的高内聚连通子图,cycle truss是一种基于cycle三角形的社区搜索模型,而现有的基于索引的cycle truss社区搜索方法存在索引空间大、搜索效率低、社区内聚性低的缺点。为了解决这一问题,提出一种基于层次树索引的最大cycle truss社区搜索方法。首先,提出了k-cycle truss分解算法,并引入了两个重要的概念:cycle三角连通与k-层次等价。基于k-层次等价设计了层次树索引TreeCIndex与表结构索引SuperTable,在此基础上,并基于这两个新的索引,提出了两个高效的cycle truss社区搜索算法。在4个真实数据集上与已有的基于TrussIndex与EquiTruss的社区搜索算法进行了比较,实验结果表明,TreeCIndex与SuperTable比TrussIndex与EquiTruss节省至少41.5%的空间,索引构建的时间节省8.2%至98.3%,且搜索最大cycle truss社区的效率分别高出了一个和两个数量级。 展开更多
关键词 有向图 社区搜索 cycle truss cycle三角形 层次等价 层次树索引
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国家级决策气象服务满意度指标及应用研究
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作者 王莉萍 章建成 +3 位作者 梁科 张立生 王维国 孙贺 《武汉理工大学学报(信息与管理工程版)》 CAS 2024年第3期503-509,共7页
为了提升国家级决策气象服务能力,构建国家级决策气象服务满意度评价的6个特性和23个基础指标,采用层次分析法确定指标权重,利用满意度模型计算用户满意度,应用波士顿矩阵分析发展潜力。基于2022年1月—6月国家级决策气象服务的满意度... 为了提升国家级决策气象服务能力,构建国家级决策气象服务满意度评价的6个特性和23个基础指标,采用层次分析法确定指标权重,利用满意度模型计算用户满意度,应用波士顿矩阵分析发展潜力。基于2022年1月—6月国家级决策气象服务的满意度调查数据,发现国家级决策气象服务的满意度为0.939,6个特性指标中准确性的满意度最低,23个基础指标中有19个指标的满意度大于0.9;6个特性指标中收获项目有3个,培育项目有1个,改进项目有2个;23个基础指标中收获项目有9个,培育项目有6个,改进项目有8个。 展开更多
关键词 决策气象服务 满意度 层次分析 波士顿矩阵 指标 应用
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全球及中国心血管疾病科技影响力评价方法研究
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作者 郝军 郎欣月 +2 位作者 王杨 曹也丁 李卫 《中国循环杂志》 CSCD 北大核心 2024年第3期279-284,共6页
目的:评估多种综合评价方法在心血管疾病科技影响力评价中的应用。方法:依据全球及中国科技影响力综合评价体系及指标权重,运用层级式多维度指标综合评价、标准化处理法、极值处理法和秩次评价法,对2016~2021年全球医疗机构心血管疾病... 目的:评估多种综合评价方法在心血管疾病科技影响力评价中的应用。方法:依据全球及中国科技影响力综合评价体系及指标权重,运用层级式多维度指标综合评价、标准化处理法、极值处理法和秩次评价法,对2016~2021年全球医疗机构心血管疾病论文影响力、全国医院心血管疾病科技影响力进行排名。结果:四种评价方法的结果一致性较高,其中标准化处理法和极值处理法的结果较为接近,秩次评价法与层级式多维度指标综合评价法的相似度较高,层级式多维度指标综合评价更能够突出高质量科技成果的重要性。结论:层级式多维度指标综合评价是将层级式指标体系、分梯队评价规则和秩次评价法整合在一起的综合评价过程,能够突出注重高质量科技成果,响应科技成果分类多维度评价的导向,具有可操作性和可推广性,为国内医疗机构综合评价实践提供一定参考。 展开更多
关键词 层级式多维度指标综合评价 心血管疾病 科技影响力
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张家口柴宣盆地浅层地下水水化学特征及水质评价
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作者 陈迎辉 马苗苗 +2 位作者 刘月东 闫佰忠 陈莹 《科学技术与工程》 北大核心 2024年第7期3010-3019,共10页
地下水作为张家口地区的主要供水水源,近年来受人类活动影响水质有恶化的趋势,影响了当地的用水安全,确定地下水化学特征与水质状况对水资源合理利用具有重要意义。基于2020年水质数据,选取Ca^(2+)、Mg^(2+)、K^(+)、Na^(+)、HCO^(-)_(3... 地下水作为张家口地区的主要供水水源,近年来受人类活动影响水质有恶化的趋势,影响了当地的用水安全,确定地下水化学特征与水质状况对水资源合理利用具有重要意义。基于2020年水质数据,选取Ca^(2+)、Mg^(2+)、K^(+)、Na^(+)、HCO^(-)_(3)、TH、pH、TDS、SO_(4)^(2-)、Cl^(-)、Al^(3+)、NO^(-)_(3)、F^(-)、Cr^(6+)等水质因子,通过数理统计法、Piper三线图、Gibbs图和岩石风化端元图对张家口柴宣盆地地区浅层地下水水化学特征进行分析,并采用模糊综合评价和改进内梅罗指数法对水质进行评价。结果表明:研究区地下水是Ca^(2+)和HCO^(-)_(3)为主的弱碱性淡水,微硬水、硬水和极硬水分别占39.51%、34.57%和25.93%;沿地下水流向,地下水化学类型由HCO_(3)-Ca·Mg、HCO_(3)-Na、SO_(4)·Cl-Na型转变为HCO_(3)-Ca·Mg、HCO_(3)-Na、SO_(4)·Cl-Ca·Mg型,水化学组分的空间分布特征主要受到硅酸盐、碳酸盐的风化溶解和人类活动影响;地下水水质整体满足III类标准,但部分地区水质较差;沿着地下水流向,水质逐渐变差,主要受原生地质环境和工业、农业污染的影响。 展开更多
关键词 水化学特征 水质评价 模糊综合评价 改进内梅罗指数法 主成分分析 系统聚类分析 柴宣盆地
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威士忌制备过程中理化指标及挥发性风味物质动态变化规律研究
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作者 陈文波 张一 +4 位作者 李小燕 杨海莺 牛丽敏 赵凯 李慧 《中国酿造》 CAS 北大核心 2024年第2期88-97,共10页
威士忌是麦芽经糖化、发酵、蒸馏、桶陈等工序制成的蒸馏酒。为明确麦汁发酵及蒸馏过程中理化指标及挥发性风味物质的变化规律,该研究以蒸馏麦芽为原料、以威士忌专用商业酵母为发酵剂制备威士忌。采用高效液相色谱(HPLC)、气相色谱-质... 威士忌是麦芽经糖化、发酵、蒸馏、桶陈等工序制成的蒸馏酒。为明确麦汁发酵及蒸馏过程中理化指标及挥发性风味物质的变化规律,该研究以蒸馏麦芽为原料、以威士忌专用商业酵母为发酵剂制备威士忌。采用高效液相色谱(HPLC)、气相色谱-质谱联用(GC-MS)等技术检测原酒浆发酵及蒸馏过程中理化指标和挥发性风味物质,并基于馏分关键风味物质(气味活度值(OAV)>1)进行主成分分析(PCA)和层次聚类分析(HCA)。结果表明,原酒浆中糖分、酒精度和主要酯类物质在第2天出现拐点;乙酸、丙酸和乳酸含量随着发酵时间增加,在第3天分别达到0.03 g/L、0.13 g/L和0.49 g/L。通过主成分分析(PCA)和层次聚类分析(HCA)可明显区分馏分。该研究结果可为威士忌发酵工艺优化及酒心摘取提供数据支撑。 展开更多
关键词 威士忌 原酒浆 理化指标 馏分 挥发性风味物质 主成分分析 层次聚类分析
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