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Graph Convolutional Networks Embedding Textual Structure Information for Relation Extraction
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作者 Chuyuan Wei Jinzhe Li +2 位作者 Zhiyuan Wang Shanshan Wan Maozu Guo 《Computers, Materials & Continua》 SCIE EI 2024年第5期3299-3314,共16页
Deep neural network-based relational extraction research has made significant progress in recent years,andit provides data support for many natural language processing downstream tasks such as building knowledgegraph,... Deep neural network-based relational extraction research has made significant progress in recent years,andit provides data support for many natural language processing downstream tasks such as building knowledgegraph,sentiment analysis and question-answering systems.However,previous studies ignored much unusedstructural information in sentences that could enhance the performance of the relation extraction task.Moreover,most existing dependency-based models utilize self-attention to distinguish the importance of context,whichhardly deals withmultiple-structure information.To efficiently leverage multiple structure information,this paperproposes a dynamic structure attention mechanism model based on textual structure information,which deeplyintegrates word embedding,named entity recognition labels,part of speech,dependency tree and dependency typeinto a graph convolutional network.Specifically,our model extracts text features of different structures from theinput sentence.Textual Structure information Graph Convolutional Networks employs the dynamic structureattention mechanism to learn multi-structure attention,effectively distinguishing important contextual features invarious structural information.In addition,multi-structure weights are carefully designed as amergingmechanismin the different structure attention to dynamically adjust the final attention.This paper combines these featuresand trains a graph convolutional network for relation extraction.We experiment on supervised relation extractiondatasets including SemEval 2010 Task 8,TACRED,TACREV,and Re-TACED,the result significantly outperformsthe previous. 展开更多
关键词 relation extraction graph convolutional neural networks dependency tree dynamic structure attention
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BARN:Behavior-Aware Relation Network for multi-label behavior detection in socially housed macaques
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作者 Sen Yang Zhi-Yuan Chen +5 位作者 Ke-Wei Liang Cai-Jie Qin Yang Yang Wen-Xuan Fan Chen-Lu Jie Xi-Bo Ma 《Zoological Research》 SCIE CSCD 2023年第6期1026-1038,共13页
Quantification of behaviors in macaques provides crucial support for various scientific disciplines,including pharmacology,neuroscience,and ethology.Despite recent advancements in the analysis of macaque behavior,rese... Quantification of behaviors in macaques provides crucial support for various scientific disciplines,including pharmacology,neuroscience,and ethology.Despite recent advancements in the analysis of macaque behavior,research on multi-label behavior detection in socially housed macaques,including consideration of interactions among them,remains scarce.Given the lack of relevant approaches and datasets,we developed the Behavior-Aware Relation Network(BARN)for multi-label behavior detection of socially housed macaques.Our approach models the relationship of behavioral similarity between macaques,guided by a behavior-aware module and novel behavior classifier,which is suitable for multi-label classification.We also constructed a behavior dataset of rhesus macaques using ordinary RGB cameras mounted outside their cages.The dataset included 65?913 labels for19 behaviors and 60?367 proposals,including identities and locations of the macaques.Experimental results showed that BARN significantly improved the baseline SlowFast network and outperformed existing relation networks.In conclusion,we successfully achieved multilabel behavior detection of socially housed macaques with both economic efficiency and high accuracy. 展开更多
关键词 Macaque behavior Drug safety assessment Multi-label behavior detection Behavioral similarity relation network
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A Survey of Knowledge Graph Construction Using Machine Learning
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作者 Zhigang Zhao Xiong Luo +1 位作者 Maojian Chen Ling Ma 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第4期225-257,共33页
Knowledge graph(KG)serves as a specialized semantic network that encapsulates intricate relationships among real-world entities within a structured framework.This framework facilitates a transformation in information ... Knowledge graph(KG)serves as a specialized semantic network that encapsulates intricate relationships among real-world entities within a structured framework.This framework facilitates a transformation in information retrieval,transitioning it from mere string matching to far more sophisticated entity matching.In this transformative process,the advancement of artificial intelligence and intelligent information services is invigorated.Meanwhile,the role ofmachine learningmethod in the construction of KG is important,and these techniques have already achieved initial success.This article embarks on a comprehensive journey through the last strides in the field of KG via machine learning.With a profound amalgamation of cutting-edge research in machine learning,this article undertakes a systematical exploration of KG construction methods in three distinct phases:entity learning,ontology learning,and knowledge reasoning.Especially,a meticulous dissection of machine learningdriven algorithms is conducted,spotlighting their contributions to critical facets such as entity extraction,relation extraction,entity linking,and link prediction.Moreover,this article also provides an analysis of the unresolved challenges and emerging trajectories that beckon within the expansive application of machine learning-fueled,large-scale KG construction. 展开更多
关键词 Knowledge graph(KG) semantic network relation extraction entity linking knowledge reasoning
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A U-Shaped Network-Based Grid Tagging Model for Chinese Named Entity Recognition
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作者 Yan Xiang Xuedong Zhao +3 位作者 Junjun Guo Zhiliang Shi Enbang Chen Xiaobo Zhang 《Computers, Materials & Continua》 SCIE EI 2024年第6期4149-4167,共19页
Chinese named entity recognition(CNER)has received widespread attention as an important task of Chinese information extraction.Most previous research has focused on individually studying flat CNER,overlapped CNER,or d... Chinese named entity recognition(CNER)has received widespread attention as an important task of Chinese information extraction.Most previous research has focused on individually studying flat CNER,overlapped CNER,or discontinuous CNER.However,a unified CNER is often needed in real-world scenarios.Recent studies have shown that grid tagging-based methods based on character-pair relationship classification hold great potential for achieving unified NER.Nevertheless,how to enrich Chinese character-pair grid representations and capture deeper dependencies between character pairs to improve entity recognition performance remains an unresolved challenge.In this study,we enhance the character-pair grid representation by incorporating both local and global information.Significantly,we introduce a new approach by considering the character-pair grid representation matrix as a specialized image,converting the classification of character-pair relationships into a pixel-level semantic segmentation task.We devise a U-shaped network to extract multi-scale and deeper semantic information from the grid image,allowing for a more comprehensive understanding of associative features between character pairs.This approach leads to improved accuracy in predicting their relationships,ultimately enhancing entity recognition performance.We conducted experiments on two public CNER datasets in the biomedical domain,namely CMeEE-V2 and Diakg.The results demonstrate the effectiveness of our approach,which achieves F1-score improvements of 7.29 percentage points and 1.64 percentage points compared to the current state-of-the-art(SOTA)models,respectively. 展开更多
关键词 Chinese named entity recognition character-pair relation classification grid tagging U-shaped segmentation network
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Outage Probability Analysis for D2D-Enabled Heterogeneous Cellular Networks with Exclusion Zone:A Stochastic Geometry Approach
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作者 Yulei Wang Li Feng +3 位作者 Shumin Yao Hong Liang Haoxu Shi Yuqiang Chen 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期639-661,共23页
Interference management is one of the most important issues in the device-to-device(D2D)-enabled heterogeneous cellular networks(HetCNets)due to the coexistence of massive cellular and D2D devices in which D2D devices... Interference management is one of the most important issues in the device-to-device(D2D)-enabled heterogeneous cellular networks(HetCNets)due to the coexistence of massive cellular and D2D devices in which D2D devices reuse the cellular spectrum.To alleviate the interference,an efficient interference management way is to set exclusion zones around the cellular receivers.In this paper,we adopt a stochastic geometry approach to analyze the outage probabilities of cellular and D2D users in the D2D-enabled HetCNets.The main difficulties contain three aspects:1)how to model the location randomness of base stations,cellular and D2D users in practical networks;2)how to capture the randomness and interrelation of cellular and D2D transmissions due to the existence of random exclusion zones;3)how to characterize the different types of interference and their impacts on the outage probabilities of cellular and D2D users.We then run extensive Monte-Carlo simulations which manifest that our theoretical model is very accurate. 展开更多
关键词 Device-to-device(D2D)-enabled heterogeneous cellular networks(HetCNets) exclusion zone stochastic geometry(SG) Matérn hard-core process(MHCP)
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New International Partner Network Launched to Further Sino-US Business Relations
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作者 Sun Yongjian LI Yinghong 《China's Foreign Trade》 2005年第16期7-11,共5页
"The network will foster newrelationship between US andChinese small and medium-size companies in 14 key busi-ness centers, generating newopportunities for US SMEs inthe China market and prosper-ity for both our ... "The network will foster newrelationship between US andChinese small and medium-size companies in 14 key busi-ness centers, generating newopportunities for US SMEs inthe China market and prosper-ity for both our great nations,"said Tim Hauser. 展开更多
关键词 US work New International Partner network Launched to Further Sino-US Business relations very
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Analysis of Factors Related to Vasovagal Response in Apheresis Blood Donors and the Establishment of Prediction Model Based on BP Neural Network Algorithm
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作者 Xin Hu Hua Xu Fengqin Li 《Journal of Clinical and Nursing Research》 2024年第6期276-283,共8页
Objective:To analyze the factors related to vessel vasovagal reaction(VVR)in apheresis donors,establish a mathematical model for predicting the correlation factors and occurrence risk,and use the prediction model to i... Objective:To analyze the factors related to vessel vasovagal reaction(VVR)in apheresis donors,establish a mathematical model for predicting the correlation factors and occurrence risk,and use the prediction model to intervene in high-risk VVR blood donors,improve the blood donation experience,and retain blood donors.Methods:A total of 316 blood donors from the Xi'an Central Blood Bank from June to September 2022 were selected to statistically analyze VVR-related factors.A BP neural network prediction model is established with relevant factors as input and DRVR risk as output.Results:First-time blood donors had a high risk of VVR,female risk was high,and sex difference was significant(P value<0.05).The blood pressure before donation and intergroup differences were also significant(P value<0.05).After training,the established BP neural network model has a minimum RMS error of o.116,a correlation coefficient R=0.75,and a test model accuracy of 66.7%.Conclusion:First-time blood donors,women,and relatively low blood pressure are all high-risk groups for VVR.The BP neural network prediction model established in this paper has certain prediction accuracy and can be used as a means to evaluate the risk degree of clinical blood donors. 展开更多
关键词 Vasovagal response Related factors Prediction BP neural network
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脓毒症心肌病B细胞相关基因筛选及ceRNA网络构建
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作者 陈美雪 曹庆飞 李静 《锦州医科大学学报》 CAS 2024年第3期70-79,共10页
目的 通过生物信息学分析筛选并验证脓毒症心肌病(septic cardiomyopathy, SCM)中B细胞相关基因(B cell-related genes, BRGs),并对其进行ceRNA网络构建,探讨BRGs在SCM中的作用机制,旨在寻找SCM早期诊断和治疗的新靶点。方法 利用GEO数... 目的 通过生物信息学分析筛选并验证脓毒症心肌病(septic cardiomyopathy, SCM)中B细胞相关基因(B cell-related genes, BRGs),并对其进行ceRNA网络构建,探讨BRGs在SCM中的作用机制,旨在寻找SCM早期诊断和治疗的新靶点。方法 利用GEO数据库中GSE79962和GSE63920数据集筛选共同差异基因(differential genes, DEGs),然后通过GO及KEGG分析其生物学功能,STRING在线工具分析蛋白之间相互作用,通过CytoScape的CytoHubba插件分析获得核心差异基因(Hub DEGs)。另一方面,通过免疫细胞浸润分析及WGCNA分析获得B细胞相关基因模块,与Hub DEGs取交集获得B细胞相关的核心基因(B cell-related hub genes, BRHGs),并在相关数据集中验证其表达情况。最后,通过在线工具及公共数据集构建并验证了B细胞相关的ceRNA网络。结果 GSE79962及GSE63920共筛选出29个共同DEGs;GO及KEGG富集分析提示其主要是通过细胞迁移、细胞转运及细胞成分运动的负向调控等方面发挥调控作用,其主要参与JAK-STAT信号途径;免疫细胞浸润结果显示,GSE79962数据集中SCM组B细胞含量明显低于对照组(P<0.05);WGCNA共筛选出1781个BRGs,与CytoScape中筛选的10个Hub DEGs取交集得到BRHG(TIMP1),在线工具预测的miRNA及长链非编码RNA(long non-coding RNA,lncRNA)分别为let-7b-5p和KCNQ1OT1,相应公共数据集验证结果均具有统计学意义。成功构建B细胞相关ceRNA网络(KCNQ1OT1/let-7b-5p/TIMP1)。结论 本研究发现并验证了参与SCM发病机制的BRHG(TIMP1),进一步探索了在SCM中B细胞介导的免疫反应可能的分子机制,为SCM的早期诊断和治疗提供了新的分子靶点。 展开更多
关键词 脓毒症心肌病 B细胞相关基因 cernA网络模型 生物信息学分析
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Adversarial Learning for Distant Supervised Relation Extraction 被引量:6
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作者 Daojian Zeng Yuan Dai +2 位作者 Feng Li R.Simon Sherratt Jin Wang 《Computers, Materials & Continua》 SCIE EI 2018年第4期121-136,共16页
Recently,many researchers have concentrated on using neural networks to learn features for Distant Supervised Relation Extraction(DSRE).These approaches generally use a softmax classifier with cross-entropy loss,which... Recently,many researchers have concentrated on using neural networks to learn features for Distant Supervised Relation Extraction(DSRE).These approaches generally use a softmax classifier with cross-entropy loss,which inevitably brings the noise of artificial class NA into classification process.To address the shortcoming,the classifier with ranking loss is employed to DSRE.Uniformly randomly selecting a relation or heuristically selecting the highest score among all incorrect relations are two common methods for generating a negative class in the ranking loss function.However,the majority of the generated negative class can be easily discriminated from positive class and will contribute little towards the training.Inspired by Generative Adversarial Networks(GANs),we use a neural network as the negative class generator to assist the training of our desired model,which acts as the discriminator in GANs.Through the alternating optimization of generator and discriminator,the generator is learning to produce more and more discriminable negative classes and the discriminator has to become better as well.This framework is independent of the concrete form of generator and discriminator.In this paper,we use a two layers fully-connected neural network as the generator and the Piecewise Convolutional Neural Networks(PCNNs)as the discriminator.Experiment results show that our proposed GAN-based method is effective and performs better than state-of-the-art methods. 展开更多
关键词 relation extraction generative adversarial networks distant supervision piecewise convolutional neural networks pair-wise ranking loss
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Material component to non-linear relation between sediment yield and drainage network development:an flume experimental study 被引量:2
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作者 JIN De-sheng, CHEN Hao, GUO Qing-wu (Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China) 《Journal of Geographical Sciences》 SCIE CSCD 2001年第3期271-281,共11页
This paper examines the experimental study on influence of material component to non-linear relation between sediment yield and drainage network development completed in the Lab. The area of flume drainage system is 8... This paper examines the experimental study on influence of material component to non-linear relation between sediment yield and drainage network development completed in the Lab. The area of flume drainage system is 81.2 m2, the longitudinal gradient and cross section slope are from 0.0348 to 0.0775 and from 0.0115 to 0.038, respectively. Different model materials with a medium diameter of 0.021 mm, 0.076 mm and 0.066 mm cover three experiments each. An artificial rainfall equipment is a sprinkler-system composed of 7 downward nozzles, distributed by hexagon type and a given rainfall intensity is 35.56 mm/hr.cm2. Three experiments are designed by process-response principle at the beginning the ψ shaped small network is dug in the flume. Running time spans are 720 m, 1440 minutes and 540 minutes for Runs I, IV and VI, respectively. Three experiments show that the sediment yield processes are characterized by delaying with a vibration. During network development the energy of a drainage system is dissipated by two ways, of which one is increasing the number of channels (rill and gully), and the other one is enlarging the channel length. The fractal dimension of a drainage network is exactly an index of energy dissipation of a drainage morphological system. Change of this index with time is an unsymmetrical concave curve. Comparison of three experiments explains that the vibration and the delaying ratio of sediment yield processes increase with material coarsening, while the number of channel decreases. The length of channel enlarges with material fining. There exists non-linear relationship between fractal dimension and sediment yield with an unsymmetrical hyperbolic curve. The absolute value of delaying ratio of the curve reduces with time running and material fining. It is characterized by substitution of situation to time. 展开更多
关键词 material component network sediment yield nonlinear relation EXPERIMENT
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Energy Efficiency Optimization for Heterogeneous Cellular Networks Modeled by Matérn Hard-Core Point Process 被引量:4
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作者 Yonghong Chen Jie Yang +1 位作者 Xuehong Cao Shibing Zhang 《China Communications》 SCIE CSCD 2020年第8期70-80,共11页
The Poisson point process(PPP) has been widely used in wireless network modeling and performance analysis due to the independence between its nodes. Therefore, it may not be a suitable model for many of the exclusive ... The Poisson point process(PPP) has been widely used in wireless network modeling and performance analysis due to the independence between its nodes. Therefore, it may not be a suitable model for many of the exclusive networks between the nodes. This paper analyzes the energy efficiency(EE) and optimizes the two-tier heterogeneous cellular networks(Het Nets). Considering the mutual exclusion between macro base stations(MBSs) distribution, the deployment of MBSs is modeled by the Matérn hard-core point process(MHCPP), and the deployment of pico base stations(PBSs) is modeled by the PPP. We adopt a simple approximation method to study the signal to interference ratio(SIR) distribution in two-tier MHCPP-PPP networks and then derive the coverage probabilities, the average data rates and the energy efficiency of Het Nets. Finally, an optimization algorithm is proposed to improve the EE of Het Nets by controlling the transmit power of PBSs. The simulation results show that the EE of a system can be effectively improved by selecting the appropriate transmit power for the PBSs. In addition, two-tier MHCPP-PPP Het Nets have higher energy efficiency than two-tier PPP-PPP Het Nets. 展开更多
关键词 energy efficiency heterogeneous cellular networks coverage probability matérn hard-core point process
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Neural Network Model for the Constitutive Relations of Soil 被引量:1
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作者 Zeng Jing, Wang J ing\|tao School of Civil Engineering and Mechanics, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China 《Wuhan University Journal of Natural Sciences》 CAS 2003年第01A期86-90,共5页
The soil constitutive relation is one of the important issues in soil mechanics. It is very difficult to establish mathematical models because of the complexity of soil mechanical behavior.... The soil constitutive relation is one of the important issues in soil mechanics. It is very difficult to establish mathematical models because of the complexity of soil mechanical behavior. We propose a new method of neural network analysis for establishing soil constitutive models. Based on triaxial experiments of sand in the laboratory, the nonlinear constitutive models of sand expressed by the neural network were set up. In comparison with Duncan\|Chang's model, the neural network method for sand modeling has been proved to be more convenient, accurate and it has a strong fault\|tolerance function. 展开更多
关键词 neural network constitutive relations constitutive model
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Spatial Interaction Network Analysis of Crude Oil Trade Relations between Countries along the Belt and Road 被引量:2
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作者 Qixin WANG Kun QIN +4 位作者 Donghai LIU Gang XU Yanqing XU Yang ZHOU Rui XIAO 《Journal of Geodesy and Geoinformation Science》 2022年第2期60-74,共15页
Based on the theories and methods of complex network,crude oil trade flows between countries along the Belt and Road(B&R,hereafter)are inserted into the Geo-space of B&R and form a spatial interaction network ... Based on the theories and methods of complex network,crude oil trade flows between countries along the Belt and Road(B&R,hereafter)are inserted into the Geo-space of B&R and form a spatial interaction network which takes the countries as nodes and takes the trade relations as edges.The networked mining and evolution analysis can provide important references for the research on trade relations among the B&R countries and the formulation of trade policy.This paper researches and discusses the construction,statistical analysis,top networks and stability of the crude oil trade network between the B&R countries from 2001 to 2020 from the perspectives of Geo-Computation for Social Sciences(GCSS)and spatial interaction.Firstly,evolutions of out-degree,in-degree,out-strength and in-strength of the top 10 countries in the crude oil trade network are computed and analyzed.Secondly,the top network method is used to explore the evolution characteristics of hierarchical structures.And finally,the sequential evolution characteristics of the crude oil trade network stability are analyzed utilizing the network stability measure method based on the trade relationship autocorrelation function.The analysis results show that Russia has the largest out-degree and out-strength,and China has the largest in-degree and in-strength.The crude oil trade volume of the top 10 import and export networks between 2001—2020 accounts for over 90%of the total trade volume of the crude oil trade network,and the proportion remains relatively stable.However,the stability of the network showed strong fluctuations in 2009,2012 and 2014,which may be closely related to major international events in these years,which could furtherly be used to build a correlation model between network volatility and major events.This paper explores how to construct and analyze the spatial interaction network of crude oil trade and can provide references for trade relations research and trade policy formulation of B&R countries. 展开更多
关键词 spatial interaction network Geo-Computation for Social Sciences(GCSS) the Belt and Road Initiative(BRI) trade relation network stability
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Joint Self-Attention Based Neural Networks for Semantic Relation Extraction 被引量:1
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作者 Jun Sun Yan Li +5 位作者 Yatian Shen Wenke Ding Xianjin Shi Lei Zhang Xiajiong Shen Jing He 《Journal of Information Hiding and Privacy Protection》 2019年第2期69-75,共7页
Relation extraction is an important task in NLP community.However,some models often fail in capturing Long-distance dependence on semantics,and the interaction between semantics of two entities is ignored.In this pape... Relation extraction is an important task in NLP community.However,some models often fail in capturing Long-distance dependence on semantics,and the interaction between semantics of two entities is ignored.In this paper,we propose a novel neural network model for semantic relation classification called joint self-attention bi-LSTM(SA-Bi-LSTM)to model the internal structure of the sentence to obtain the importance of each word of the sentence without relying on additional information,and capture Long-distance dependence on semantics.We conduct experiments using the SemEval-2010 Task 8 dataset.Extensive experiments and the results demonstrated that the proposed method is effective against relation classification,which can obtain state-ofthe-art classification accuracy just with minimal feature engineering. 展开更多
关键词 Self-attention relation extraction neural networks
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Uncertain Relation Suited to Overfitting of BP Neural Network 被引量:3
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作者 任继平 李祚泳 江春华 《Journal of Electronic Science and Technology of China》 2004年第1期53-57,共5页
A general uncertainty relation between the change of weighted value which represents learning ability and the discrimination error of unlearning sample sets which represents generalization ability is revealed in the m... A general uncertainty relation between the change of weighted value which represents learning ability and the discrimination error of unlearning sample sets which represents generalization ability is revealed in the modeling of back propagation (BP) neural network. Tests of numerical simulation for multitype of complicated functions are carried out to determine the value distribution (1×10?5~5×10?4) of overfitting parameter in the uncertainty relation. Based on the uncertainty relation, the overfitting in the training process of given sample sets using BP neural network can be judged. 展开更多
关键词 back progagation neural network OVERFITTING learning ability generalization ability uncertainty relation
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Function chain neural network prediction on heat transfer performance of oscillating heat pipe based on grey relational analysis 被引量:12
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作者 鄂加强 李玉强 龚金科 《Journal of Central South University》 SCIE EI CAS 2011年第5期1733-1737,共5页
As for the factors affecting the heat transfer performance of complex and nonlinear oscillating heat pipe (OHP),grey relational analysis (GRA) was used to deal with the relationship between heat transfer rate of a loo... As for the factors affecting the heat transfer performance of complex and nonlinear oscillating heat pipe (OHP),grey relational analysis (GRA) was used to deal with the relationship between heat transfer rate of a looped copper-water OHP and charging ratio,inner diameter,inclination angel,heat input,number of turns,and the main influencing factors were defined.Then,forecasting model was obtained by using main influencing factors (such as charging ratio,interior diameter,and inclination angel) as the inputs of function chain neural network.The results show that the relative average error between the predicted and actual value is 4%,which illustrates that the function chain neural network can be applied to predict the performance of OHP accurately. 展开更多
关键词 函数链神经网络 灰色关联分析 神经网络预测 传输性能 振荡热管 影响因素 平均相对误差 传热性能
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Comprehensive evaluation of communication network based on network carrying and associating relation
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作者 周万银 李明辉 夏靖波 《Journal of Beijing Institute of Technology》 EI CAS 2013年第3期410-416,共7页
In order to solve the problem of integrated management in different types of networks, a comprehensive evaluation method for a communication network is presented via network carrying and associating relation. Based on... In order to solve the problem of integrated management in different types of networks, a comprehensive evaluation method for a communication network is presented via network carrying and associating relation. Based on the abstract and analysis of network relation, the principle and procedure of the evaluation method are discussed. The method considers the effect of individual di- versity of network running indicator, and reflects the contribution and associating degree of network carrying relation. Experiment results verify that the proposed method is correct and efficient. The re- search provides a new idea for the future network management. 展开更多
关键词 network comprehensive evaluation carrying and associating relation Petri net
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Relationships Between Fractal Road and Drainage Networks in Wuling Mountainous Area:Another Symmetric Understanding of Human-Environment Relations 被引量:2
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作者 LIU Cheng-liang DUAN De-zhong ZHANG Hong 《Journal of Mountain Science》 SCIE CSCD 2014年第4期1060-1069,共10页
Symmetrical relationships between humans and their environment have been referred to as an extension of symmetries in the human geographical system and have drawn great attention.This paper explored the symmetry betwe... Symmetrical relationships between humans and their environment have been referred to as an extension of symmetries in the human geographical system and have drawn great attention.This paper explored the symmetry between physical and human systems through fractal analysis of the road and drainage networks in Wuling mountainous area. We found that both the road and drainage networks reflect weak clustering distributions. The evolution of the road network shared a significant self-organizing composition, while the drainage network showed obvious double fractal characteristics The geometric fractal dimension of the road network was larger than that of the drainage network. In addition, when assigned a weight relating to hierarchy or length, neither the road network nor drainage network showed a fractal property. These findings indicated that the fractal evolution of the road network shared certain similarities with fractal distribution of the drainage network. The symmetry between the two systems resulted from an interactive process of destroying symmetry at the lower order and reconstructing symmetry at the higher order. The relationships between the fractal dimensions of the rural-urban road network, the drainage network and the urban system indicated that the development of this area was to achieve the symmetrical isomorphism of physical-human geographical systems. 展开更多
关键词 人与环境关系 道路网络 武陵山区 分形分析 排水网络 对称性 排水管网 地域系统
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Artificial neural network model of constitutive relations for shock-prestrained copper
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作者 杨扬 朱远志 +3 位作者 李正华 张新明 杨立斌 陈志永 《中国有色金属学会会刊:英文版》 CSCD 2001年第2期210-212,共3页
Data from the deformation on Split Hopkinson Bar were used for constructing an artificial neural network model. When putting the thermodynamic parameters of the metals into the trained network model, the corresponding... Data from the deformation on Split Hopkinson Bar were used for constructing an artificial neural network model. When putting the thermodynamic parameters of the metals into the trained network model, the corresponding yielding stress can be predicted. The results show that the systematic error is small when the objective function is 0.5 , the number of the nodes in the hidden layer is 6 and the learning rate is about 0.1 , and the accuracy of the rate error is less than 3%. [ 展开更多
关键词 shock prestrain constitutive relations artificial neural network model
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The Invulnerability of Directed Interdependent Networks with Multiple Dependency Relations
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作者 Hanbing Gao Zhiming Ma 《Applied Mathematics》 2018年第10期1104-1115,共12页
The paper aims to study the invulnerability of directed interdependent networks with multiple dependency relations: dependent and supportive. We establish three models and simulate in three network systems to deal wit... The paper aims to study the invulnerability of directed interdependent networks with multiple dependency relations: dependent and supportive. We establish three models and simulate in three network systems to deal with this question. To improve network invulnerability, we’d better avoid dependent relations transmission and add supportive relations symmetrically. 展开更多
关键词 Interdependent networkS DEPENDENCY relationS INVULNERABILITY
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