期刊文献+
共找到608篇文章
< 1 2 31 >
每页显示 20 50 100
Location of Electric Vehicle Charging Station Based on Spatial Clustering and Multi-hierarchical Fuzzy Evaluation 被引量:2
1
作者 Wang Meng Liu Kai 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2017年第1期89-96,共8页
For the charging station construction of electric vehicle,location selecting is a key issue.There are two problems in location selection of the electric vehicle charging station.One is determining the location of char... For the charging station construction of electric vehicle,location selecting is a key issue.There are two problems in location selection of the electric vehicle charging station.One is determining the location of charging station;the other is evaluating the location of charging station.To determine the charging station location,an spatial clustering algorithm is proposed and programmed.The example simulation shows the effectiveness of the spatial clustering algorithm.To evaluate the charging station location,a multi-hierarchical fuzzy method is proposed.Based on the location factors of electric vehicle charging station,the hierarchical evaluation structure of electric vehicle charging station location is constructed,including three levels,4first-class factors and 14second-class factors.The fuzzy multi-hierarchical evaluation model and algorithm are built.The analysis results show that the multi-hierarchical fuzzy method can reasonably complete the electric vehicle charging station location evaluation. 展开更多
关键词 electric vehicle CHARGING STATION spatial clustering multi-hierarchical fuzzy evaluation
在线阅读 下载PDF
Unicast Network Topology Inference Algorithm Based on Hierarchical Clustering
2
作者 肖甫 是晨航 +1 位作者 黄凯祥 王汝传 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2015年第6期591-599,共9页
Network topology inference is one of the important applications of network tomography.Traditional network topology inference may impact network normal operation due to its generation of huge data traffic.A unicast net... Network topology inference is one of the important applications of network tomography.Traditional network topology inference may impact network normal operation due to its generation of huge data traffic.A unicast network topology inference is proposed to use time to live(TTL)for layering and classify nodes layer by layer based on the similarity of node pairs.Finally,the method infers logical network topology effectively with self-adaptive combination of previous results.Simulation results show that the proposed method holds a high accuracy of topology inference while decreasing network measuring flow,thus improves measurement efficiency. 展开更多
关键词 network topology inference network tomography hierarchical clustering time to live(TTL)
在线阅读 下载PDF
Fair hierarchical clustering of substations based on Gini coefficient
3
作者 Dajun Si Wenyue Hu +1 位作者 Zilin Deng Yanhui Xu 《Global Energy Interconnection》 EI CAS CSCD 2021年第6期576-586,共11页
For the load modeling of a large power grid,the large number of substations covered by it must be segregated into several categories and,thereafter,a load model built for each type.To address the problem of skewed clu... For the load modeling of a large power grid,the large number of substations covered by it must be segregated into several categories and,thereafter,a load model built for each type.To address the problem of skewed clustering tree in the classical hierarchical clustering method used for categorizing substations,a fair hierarchical clustering method is proposed in this paper.First,the fairness index is defined based on the Gini coefficient.Thereafter,a hierarchical clustering method is proposed based on the fairness index.Finally,the clustering results are evaluated using the contour coefficient and the t-SNE two-dimensional plane map.The substations clustering example of a real large power grid considered in this paper illustrates that the proposed fair hierarchical clustering method can effectively address the problem of the skewed clustering tree with high accuracy. 展开更多
关键词 Load modeling Substation clustering Gini coefficient hierarchical clustering Contour coefficient
在线阅读 下载PDF
ADC-DL:Communication-Efficient Distributed Learning with Hierarchical Clustering and Adaptive Dataset Condensation
4
作者 Zhipeng Gao Yan Yang +1 位作者 Chen Zhao Zijia Mo 《China Communications》 SCIE CSCD 2022年第12期73-85,共13页
The rapid growth of modern mobile devices leads to a large number of distributed data,which is extremely valuable for learning models.Unfortunately,model training by collecting all these original data to a centralized... The rapid growth of modern mobile devices leads to a large number of distributed data,which is extremely valuable for learning models.Unfortunately,model training by collecting all these original data to a centralized cloud server is not applicable due to data privacy and communication costs concerns,hindering artificial intelligence from empowering mobile devices.Moreover,these data are not identically and independently distributed(Non-IID)caused by their different context,which will deteriorate the performance of the model.To address these issues,we propose a novel Distributed Learning algorithm based on hierarchical clustering and Adaptive Dataset Condensation,named ADC-DL,which learns a shared model by collecting the synthetic samples generated on each device.To tackle the heterogeneity of data distribution,we propose an entropy topsis comprehensive tiering model for hierarchical clustering,which distinguishes clients in terms of their data characteristics.Subsequently,synthetic dummy samples are generated based on the hierarchical structure utilizing adaptive dataset condensation.The procedure of dataset condensation can be adjusted adaptively according to the tier of the client.Extensive experiments demonstrate that the performance of our ADC-DL is more outstanding in prediction accuracy and communication costs compared with existing algorithms. 展开更多
关键词 distributed learning Non-IID data partition hierarchical clustering adaptive dataset condensation
在线阅读 下载PDF
Hierarchical and probabilistic quantum information splitting of an arbitrary two-qubit state via two cluster states 被引量:1
5
作者 Wen-Ming Guo Lei-Ru Qin 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第11期382-389,共8页
Based on non-maximally entangled four-particle cluster states, we propose a new hierarchical information splitting protocol to probabilistically realize the quantum state sharing of an arbitrary unknown two-qubit stat... Based on non-maximally entangled four-particle cluster states, we propose a new hierarchical information splitting protocol to probabilistically realize the quantum state sharing of an arbitrary unknown two-qubit state. In this scheme, the sender transmits the two-qubit secret state to three agents who are divided into two grades with two Bell-state measurements,and broadcasts the measurement results via a classical channel. One agent is in the upper grade and two agents are in the lower grade. The agent in the upper grade only needs to cooperate with one of the other two agents to recover the secret state but both of the agents in the lower grade need help from all of the agents. Every agent who wants to recover the secret state needs to introduce two ancillary qubits and performs a positive operator-valued measurement(POVM) instead of the usual projective measurement. Moreover, due to the symmetry of the cluster state, we extend this protocol to multiparty agents. 展开更多
关键词 cluster state hierarchical quantum information splitting positive operator-valued measurement (POVM)
在线阅读 下载PDF
The reflection of hierarchical cluster analysis of co-occurrence matrices in SPSS 被引量:5
6
作者 Qiuju ZHOU Fuhai LENG Loet LEYDESDORFF 《Chinese Journal of Library and Information Science》 2015年第2期11-24,共14页
Purpose: To discuss the problems arising from hierarchical cluster analysis of co-occurrence matrices in SPSS, and the corresponding solutions. Design/methodology/approach: We design different methods of using the S... Purpose: To discuss the problems arising from hierarchical cluster analysis of co-occurrence matrices in SPSS, and the corresponding solutions. Design/methodology/approach: We design different methods of using the SPSS hierarchical clustering module for co-occurrence matrices in order to compare these methods. We offer the correct syntax to deactivate the similarity algorithm for clustering analysis within the hierarchical clustering module of SPSS. Findings: When one inputs co-occurrence matrices into the data editor of the SPSS hierarchical clustering module without deactivating the embedded similarity algorithm, the program calculates similarity twice, and thus distorts and overestimates the degree of similarity. Practical implications: We offer the correct syntax to block the similarity algorithm for clustering analysis in the SPSS hierarchical clustering module in the case of co-occurrence matrices. This syntax enables researchers to avoid obtaining incorrect results. Originality/value: This paper presents a method of editing syntax to prevent the default use of a similarity algorithm for SPSS's hierarchical clustering module. This will help researchers, especially those from China, to properly implement the co-occurrence matrix when using SPSS for hierarchical cluster analysis, in order to provide more scientific and rational results. 展开更多
关键词 Co-occurrence matrices hierarchical cluster analysis SPSS Similarity algorithm The syntax editor
在线阅读 下载PDF
Energy-Efficient Multi-Mode Clusters Maintenance(M^2CM) for Hierarchical Wireless Sensor Networks
7
作者 Xiangdong Hu Zhulin Liu 《China Communications》 SCIE CSCD 2017年第6期1-12,共12页
How to energy-efficiently maintain the topology of wireless sensor networks(WSNs) is still a difficult problem because of their numerous nodes,highly dynamic nature,varied application scenarios and limited resources.A... How to energy-efficiently maintain the topology of wireless sensor networks(WSNs) is still a difficult problem because of their numerous nodes,highly dynamic nature,varied application scenarios and limited resources.An energy-efficient multi-mode clusters maintenance(M2CM) method is proposed based on localized and event-driven mechanism in this work,which is different from the conventional clusters maintenance model with always periodically re-clustered among the whole network style based on time-trigger for hierarchical WSNs.M2 CM can meet such demands of clusters maintenance as adaptive local maintenance for the damaged clusters according to its changes in time and space field.,the triggers of M2 CM include such events as nodes' residual energy being under the threshold,the load imbalance of cluster head,joining in or exiting from any cluster for new node or disable one,etc.Based on neighboring relationship of the damaged clusters,one can start a single cluster(inner-cluster) maintenance or clusters(inter-cluster) maintenance program to meet diverse demands in the topology management of hierarchical WSNs.The experiment results based on NS2 simulation show that the proposed method can significantly save energy used in maintaining a damaged network,effectively narrow down the influenced area of clusters maintenance,and increase transmitted data and prolong lifetime of network compared to the traditional schemes. 展开更多
关键词 hierarchical iterative clustering MULTI-MODE EVENT-DRIVEN adaptive ENERGY-EFFICIENT
在线阅读 下载PDF
Comparison of Clustering Methods in Yeast Saccharomyces Cerevisiae
8
作者 Wen Wang Ni-Ni Rao Xi Chen Shang-Lei Xu 《Journal of Electronic Science and Technology》 CAS 2010年第2期178-182,共5页
In recent years, microarray technology has been widely applied in biological and clinical studies for simultaneous monitoring of gene expression in thousands of genes. Gene clustering analysis is found useful for disc... In recent years, microarray technology has been widely applied in biological and clinical studies for simultaneous monitoring of gene expression in thousands of genes. Gene clustering analysis is found useful for discovering groups of correlated genes potentially co-regulated or associated to the disease or conditions under investigation. Many clustering methods including k-means, fuzzy c-means, and hierarchical clustering have been widely used in literatures. Yet no comprehensive comparative study has been performed to evaluate the effectiveness of these methods, specially, in yeast saccharomyces cerevisiae. In this paper, these three gene clustering methods are compared. Classification accuracy and CPU time cost are employed for measuring performance of these algorithms. Our results show that hierarchical clustering outperforms k-means and fuzzy c-means clustering. The analysis provides deep insight to the complicated gene clustering problem of expression profile and serves as a practical guideline for routine microarray cluster analysis of gene expression. 展开更多
关键词 Fuzzy c-means hierarchical clustering K-MEANS yeast saecharomyees cerevisiae.
在线阅读 下载PDF
A Multilevel Secure Relation-Hierarchical Data Model for a Secure DBMS
9
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
在线阅读 下载PDF
上海地产猪肉品质主要评价指标的筛选及分级标准的建立 被引量:2
10
作者 邓波 马颖清 +6 位作者 陈柔含 白寅霜 张岩 杨晓君 李柚 王金斌 沈秀平 《食品安全质量检测学报》 2025年第3期184-194,共11页
目的对猪肉分等分级和优质优价构建合理的猪肉品质评价体系。方法本研究以市面常见杜长大三元杂交猪为对照,采集中国上海地产7种猪背最长肌进行肉质外观、质构、营养、风味物质等各项指标测定,并确定地产猪肉品质的13项主要评价指标。... 目的对猪肉分等分级和优质优价构建合理的猪肉品质评价体系。方法本研究以市面常见杜长大三元杂交猪为对照,采集中国上海地产7种猪背最长肌进行肉质外观、质构、营养、风味物质等各项指标测定,并确定地产猪肉品质的13项主要评价指标。为进一步构建上海地产猪肉品质分级标准,应用因子分析、聚类分析、层次分析建立综合评价体系。结果通过因子分析,在选定的13项指标中确定7项指标(水分含量、电导率、剪切力、铁、脂肪、肌苷酸和天冬氨酸)作为主因子,其方差贡献率高达83.829%。利用聚类分析及层析分析,按照所得的7个品质指标建立3个不同等级的评分标准。结论本研究建立上海地区完整的猪肉品质评价模型和分级评分标准,实现了上海地区猪肉品质的精准把控,也为地方猪肉品质评价提供了借鉴。 展开更多
关键词 猪肉 聚类分析 层次分析 品质评价模型 分级评分标准
在线阅读 下载PDF
基于社会化聆听的服装品牌个性维度构建与量化
11
作者 章冰珏 宋琨 顾新荣 《丝绸》 北大核心 2025年第5期22-33,共12页
品牌个性是品牌资产的重要组成部分。本文旨在结合社会化聆听数据与自然语言处理技术,构建服装品牌个性维度框架,并提出量化方法。本文通过采集社交媒体上消费者关于服装品牌的推文,运用文本分词和情感分析提取品牌核心词汇,并借助词嵌... 品牌个性是品牌资产的重要组成部分。本文旨在结合社会化聆听数据与自然语言处理技术,构建服装品牌个性维度框架,并提出量化方法。本文通过采集社交媒体上消费者关于服装品牌的推文,运用文本分词和情感分析提取品牌核心词汇,并借助词嵌入与聚类方法筛选出品牌个性词汇并构建维度框架。最后,利用TF-IDF方法对不同品牌在个性维度上的表现进行量化分析。本文基于特质论构建涵盖5主维度、28子维度和176核心词汇的服装品牌个性维度,系统捕捉社交媒体语境下的品牌个性特征,同时验证了TF-IDF方法在品牌个性测量中的应用,可为品牌追踪与管理提供新的理论基础和方法论支持。 展开更多
关键词 品牌个性 社会化聆听 自然语言处理 情感分析 词嵌入 GPT模型 零样本学习 层次聚类
在线阅读 下载PDF
基于药物效用度的用药规律研究
12
作者 胥微 游聪 +1 位作者 钟远明 卢敏 《现代信息科技》 2025年第1期127-133,共7页
传统的数据挖掘方法一般从组方中所有的药物出发,挖掘药物的用药规律,计算量大,且仅仅基于药物频次对组方进行研究,忽略了药物剂量因素,难以发现频次低但剂量占比高的具有良好疗效的药物。针对以上问题,提出一种改进的基于效用度(Effect... 传统的数据挖掘方法一般从组方中所有的药物出发,挖掘药物的用药规律,计算量大,且仅仅基于药物频次对组方进行研究,忽略了药物剂量因素,难以发现频次低但剂量占比高的具有良好疗效的药物。针对以上问题,提出一种改进的基于效用度(Effect Degree,ED)核心药物发现算法,并将基于效用度的点式互信息(Pointwise Mutual Information with Herb Pair ED,PMIED)与节点度结合,定义一种新的加权相关系数作为药物权重,在所发现的核心药物中运用层次聚类算法研究用药规律。实验结果表明,该算法可有效挖掘出组方中的核心药物,经过分析,所发现的核心药物和药物组合均对痰瘀互阻证具有良好疗效。 展开更多
关键词 用药规律 效用度 核心药物 节点度 层次聚类
在线阅读 下载PDF
基于层次聚类算法的结构损伤识别研究
13
作者 何欣 蔡金标 刘鸾翔 《低温建筑技术》 2025年第3期20-25,共6页
为探究层次聚类算法在结构健康检测中的应用,文中基于压电阻抗(EMI)技术,对一维钢梁和二维铝板损伤过程的阻抗变化进行监测。引入层次聚类算法进行结构损伤识别的定量研究,通过与均方根差RMSD指标法的比较,结果表明两种方法均能比较直... 为探究层次聚类算法在结构健康检测中的应用,文中基于压电阻抗(EMI)技术,对一维钢梁和二维铝板损伤过程的阻抗变化进行监测。引入层次聚类算法进行结构损伤识别的定量研究,通过与均方根差RMSD指标法的比较,结果表明两种方法均能比较直观地判断是否存在损伤。层次聚类算法将结构的损伤分为无损伤、小损伤、中损伤、大损伤四大类的方法更为合理。层次聚类算法的欧氏距离定位方法,在概念上更加清晰,为结构健康检测提供新途径。 展开更多
关键词 EMI技术 RMSD指标法 层次聚类算法 损伤识别 阻抗谱
在线阅读 下载PDF
面向自然资源资产清查的云南森林资源均质区划分研究
14
作者 刘浩 郑璞冰 +1 位作者 叶江霞 魏晓燕 《西南林业大学学报(自然科学)》 北大核心 2025年第1期137-145,共9页
根据云南省各县与森林资源质量相关的森林起源、单位面积蓄积量、海拔、坡度、地形起伏、气候条件及社会经济等17个因子的空间差异,以县级单位之间的空间距离表示森林资源的相似程度,借助K-均值聚类和层次聚类的方法将云南省划分为空间... 根据云南省各县与森林资源质量相关的森林起源、单位面积蓄积量、海拔、坡度、地形起伏、气候条件及社会经济等17个因子的空间差异,以县级单位之间的空间距离表示森林资源的相似程度,借助K-均值聚类和层次聚类的方法将云南省划分为空间上较一致的均质单元,揭示云南森林资源空间分异性。结果表明:K-均值聚类方法能更有效将云南省划分为6个森林资源均质区;且在实际应用中K-均值聚类的可操作性更强,结果更趋聚集连通性。研究除考虑森林资源禀赋外,将经济与人为活动因素纳入聚类分析中,可以更为客观地反映森林资源资产区域差异。研究可为构建国家森林资源资产清查价格体系及资产核算提供参考,对于支撑国家森林资源清查工作具有重要理论与实践价值。 展开更多
关键词 空间分异性 K-均值聚类 层次聚类 社会经济属性 均质区划分
在线阅读 下载PDF
基于虚拟同轨网络的星间组网通信系统设计
15
作者 魏骁 王朝 +2 位作者 孙天旭 叶葆巍 张博 《中国空间科学技术(中英文)》 北大核心 2025年第2期114-123,共10页
针对低轨Walker星座组网通信的应用背景,提出了一种基于分层分簇式路由协议的完整卫星组网通信系统架构,涵盖了网络层、数据链路层和物理层设计。为便于分析,首先建立了一种典型的低轨Walker星座模型,分析了其在不同轨道相位因子和轨道... 针对低轨Walker星座组网通信的应用背景,提出了一种基于分层分簇式路由协议的完整卫星组网通信系统架构,涵盖了网络层、数据链路层和物理层设计。为便于分析,首先建立了一种典型的低轨Walker星座模型,分析了其在不同轨道相位因子和轨道倾角下的轨道拓扑构型特性和卫星间的通信可见性。其次基于构建的星座拓扑提出“虚拟同轨”的概念,并利用“虚拟同轨”建立了双层环状网络。最后,针对此双层环状网络,在网络层、数据链路层和物理层分别给出了具体的设计方案,以实现同轨和异轨卫星的信息交互。设计的通信协议栈针对性地考虑了Walker星座的跨轨道信息传递调度问题,兼顾了传输效率和设计复杂度,对相似构型的其他Walker星座星间组网体系的设计具有一定参考价值。 展开更多
关键词 低轨Walker星座 星间链路通信 分层分簇 虚拟同轨 系统设计
在线阅读 下载PDF
含可再生能源和储能系统的主动配电网系统协同规划
16
作者 王文宾 朱燕舞 +3 位作者 赵辉 李泽卿 李征 范曾 《中国测试》 北大核心 2025年第4期128-136,159,共10页
为实现可再生能源系统、储能系统和配电网之间的协同规划,提出一种考虑经济性、可靠性和可再生能源渗透率等多目标、多层次的主动配电网扩展规划方法。首先,该方法采用K-means聚类方法处理可再生能源和负荷需求的不确定性,建立典型日常... 为实现可再生能源系统、储能系统和配电网之间的协同规划,提出一种考虑经济性、可靠性和可再生能源渗透率等多目标、多层次的主动配电网扩展规划方法。首先,该方法采用K-means聚类方法处理可再生能源和负荷需求的不确定性,建立典型日常情景模型;其次,为实现可再生能源、储能系统和配电网的协同规划,基于leaderfollower分层优化策略,以运行成本、可靠性和新能源渗透率为优化目标,结合设备健康指数,构建3层优化模型,并采用粒子群算法进行求解;最后,将3种不同的仿真方案运用到IEEE33节点的扩建规划上,并对仿真结果进行对比分析。仿真结果表明:按照该文提出方案升级后配电网的运行成本为15663.61$,新能源渗透率为18.53%,和另外两种方案相比,运行成本分别降低5.89%和4.03%,新能源渗透率分别增加18.53%和16.93%,可证明该方法的可用性和有效性。 展开更多
关键词 主动配电网 K-MEANS聚类 配电网规划 分层优化
在线阅读 下载PDF
不同地区来源浓香型白酒窖泥古菌群落结构分析
17
作者 马龙 燕伟 +3 位作者 王淑玉 林一心 尉军强 唐云 《中国酿造》 北大核心 2025年第2期185-190,共6页
该研究以甘肃陇南(JH)、四川宜宾(LZ、YQ、XG)、四川成都(TC)地区浓香型白酒厂的窖泥样品为研究对象,基于高通量测序技术分析窖泥古菌菌群多样性,并采用主成分分析(PCA)和层次聚类分析(HCA)探究不同地区酒厂窖泥古菌菌群的差异性。结果... 该研究以甘肃陇南(JH)、四川宜宾(LZ、YQ、XG)、四川成都(TC)地区浓香型白酒厂的窖泥样品为研究对象,基于高通量测序技术分析窖泥古菌菌群多样性,并采用主成分分析(PCA)和层次聚类分析(HCA)探究不同地区酒厂窖泥古菌菌群的差异性。结果表明,5种窖泥样品的操作分类单元(OTUs)分布情况类似,其中,LZ窖泥样品的古菌菌群丰富度和多样性均最高。在门水平上,5种窖泥样品中的绝对优势菌门均为广古菌门(Euryarchaeota)(相对丰度均>99%)。在属水平上,共有的优势古菌属为甲烷杆菌属(Methanobacterium)、甲烷短杆菌属(Methanobrevibacter)(相对丰度均≥10%)。此外,样品TC和JH的优势古菌属还包括甲烷八叠球菌属(Methanosarcina)(相对丰度分别为18.90%、25.18%);样品LZ的优势古菌属还包括甲烷囊菌属(Methanoculleus)(相对丰度为34.25%)和拟甲烷球菌属(Methanomethylophilus)(相对丰度为18.87%)。PCA及HCA结果表明,样品JH、TC之间及样品XG、YQ之间的古菌菌群结构相似,样品LZ的古菌菌群结构与其余窖泥样品存在较大差异。 展开更多
关键词 浓香型白酒 窖泥 古菌群落 高通量测序 层次聚类分析
在线阅读 下载PDF
基于并行解码和聚类的课程实体关系联合抽取
18
作者 孙丽郡 徐行健 孟繁军 《应用科学学报》 北大核心 2025年第2期334-347,共14页
实体关系联合抽取作为构建知识图谱的核心环节,旨在从非结构化文本中提取实体-关系三元组。针对现有联合抽取方法在解码时未能有效处理实体关系间的相互作用,导致对语境理解不足,产生冗余信息等问题,提出一种基于并行解码和聚类的实体... 实体关系联合抽取作为构建知识图谱的核心环节,旨在从非结构化文本中提取实体-关系三元组。针对现有联合抽取方法在解码时未能有效处理实体关系间的相互作用,导致对语境理解不足,产生冗余信息等问题,提出一种基于并行解码和聚类的实体关系联合抽取模型。首先,利用BERT(bidirectional encoder representations from transformers)模型进行文本编码,获取语义信息丰富的字符向量。其次,采用非自回归并行解码器增强实体关系间的交互,并引入层次凝聚聚类算法及多数投票机制进一步优化解码结果以捕获语境信息,减少冗余信息。最后,生成高质量的三元组集合,以构建课程知识图谱。为评估该方法的性能,在公共数据集NYT和WebNLG以及自建C语言数据集上进行实验,结果表明,该方法在精确率和F1值上优于其他对比模型。 展开更多
关键词 联合抽取 并行解码 层次凝聚聚类 多数投票机制 课程知识图谱
在线阅读 下载PDF
高灵敏度X射线荧光光谱结合化学计量学对鞋底材料的快速检验
19
作者 王会荣 姜红 +4 位作者 宋彩芳 刘姝君 郑先云 李桂兰 韩玮 《化学研究与应用》 北大核心 2025年第3期655-661,共7页
为实现对不同鞋底材料的快速、准确鉴别,采用高灵敏度X射线荧光光谱对88个不同品牌、不同种类的鞋底材料进行测定。根据测试结果,初步把样品分为4类。结合化学计量学,对数据进行分析,首先用Ward法进行凝聚式层次聚类,然后建立决策树随... 为实现对不同鞋底材料的快速、准确鉴别,采用高灵敏度X射线荧光光谱对88个不同品牌、不同种类的鞋底材料进行测定。根据测试结果,初步把样品分为4类。结合化学计量学,对数据进行分析,首先用Ward法进行凝聚式层次聚类,然后建立决策树随机森林分类预测模型,数据表明随机森林的训练集正确率为100%,测试集的正确率为89%。进一步根据所含元素可以对鞋底材料进行准确识别。高灵敏度X射线荧光光谱法结合化学计量学可以对鞋底材料进行快速有效的检验,为未知鞋底材料溯源提供了一种新的思路。 展开更多
关键词 鞋底材料 高灵敏度X射线荧光光谱法 层次聚类 决策树 随机森林
在线阅读 下载PDF
一种基于分级控制的D2D资源分配方法分析
20
作者 肖清华 《邮电设计技术》 2025年第1期39-42,共4页
动态分析待接入D2D用户对的业务需求,结合蜂窝用户的资源占用情况,对系统可利用资源进行统一评估。计算出待接入D2D用户对的分级评估值,结合阈值参数,差异化区分出3种分级控制场景。最后,采用Matlab工具对本算法和之前的模糊聚类算法(... 动态分析待接入D2D用户对的业务需求,结合蜂窝用户的资源占用情况,对系统可利用资源进行统一评估。计算出待接入D2D用户对的分级评估值,结合阈值参数,差异化区分出3种分级控制场景。最后,采用Matlab工具对本算法和之前的模糊聚类算法(包括功控及无功控)进行了仿真对比验证。结果表明,本算法在接入次数累计分布及系统容量等方面有着更均衡的性能提升。 展开更多
关键词 5G D2D 分级控制 模糊聚类 资源分配
在线阅读 下载PDF
上一页 1 2 31 下一页 到第
使用帮助 返回顶部