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A Multi-Level Semantic Constraint Approach for Highway Tunnel Scene Twin Modeling 被引量:1
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作者 LI Yufei XIE Yakun +3 位作者 CHEN Mingzhen ZHAO Yaoji TU Jiaxing HU Ya 《Journal of Geodesy and Geoinformation Science》 2025年第2期37-56,共20页
As a key node of modern transportation network,the informationization management of road tunnels is crucial to ensure the operation safety and traffic efficiency.However,the existing tunnel vehicle modeling methods ge... As a key node of modern transportation network,the informationization management of road tunnels is crucial to ensure the operation safety and traffic efficiency.However,the existing tunnel vehicle modeling methods generally have problems such as insufficient 3D scene description capability and low dynamic update efficiency,which are difficult to meet the demand of real-time accurate management.For this reason,this paper proposes a vehicle twin modeling method for road tunnels.This approach starts from the actual management needs,and supports multi-level dynamic modeling from vehicle type,size to color by constructing a vehicle model library that can be flexibly invoked;at the same time,semantic constraint rules with geometric layout,behavioral attributes,and spatial relationships are designed to ensure that the virtual model matches with the real model with a high degree of similarity;ultimately,the prototype system is constructed and the case region is selected for the case study,and the dynamic vehicle status in the tunnel is realized by integrating real-time monitoring data with semantic constraints for precise virtual-real mapping.Finally,the prototype system is constructed and case experiments are conducted in selected case areas,which are combined with real-time monitoring data to realize dynamic updating and three-dimensional visualization of vehicle states in tunnels.The experiments show that the proposed method can run smoothly with an average rendering efficiency of 17.70 ms while guaranteeing the modeling accuracy(composite similarity of 0.867),which significantly improves the real-time and intuitive tunnel management.The research results provide reliable technical support for intelligent operation and emergency response of road tunnels,and offer new ideas for digital twin modeling of complex scenes. 展开更多
关键词 highway tunnel twin modeling multi-level semantic constraints tunnel vehicles multidimensional modeling
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Enhancing Relational Triple Extraction in Specific Domains:Semantic Enhancement and Synergy of Large Language Models and Small Pre-Trained Language Models 被引量:1
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作者 Jiakai Li Jianpeng Hu Geng Zhang 《Computers, Materials & Continua》 SCIE EI 2024年第5期2481-2503,共23页
In the process of constructing domain-specific knowledge graphs,the task of relational triple extraction plays a critical role in transforming unstructured text into structured information.Existing relational triple e... In the process of constructing domain-specific knowledge graphs,the task of relational triple extraction plays a critical role in transforming unstructured text into structured information.Existing relational triple extraction models facemultiple challenges when processing domain-specific data,including insufficient utilization of semantic interaction information between entities and relations,difficulties in handling challenging samples,and the scarcity of domain-specific datasets.To address these issues,our study introduces three innovative components:Relation semantic enhancement,data augmentation,and a voting strategy,all designed to significantly improve the model’s performance in tackling domain-specific relational triple extraction tasks.We first propose an innovative attention interaction module.This method significantly enhances the semantic interaction capabilities between entities and relations by integrating semantic information fromrelation labels.Second,we propose a voting strategy that effectively combines the strengths of large languagemodels(LLMs)and fine-tuned small pre-trained language models(SLMs)to reevaluate challenging samples,thereby improving the model’s adaptability in specific domains.Additionally,we explore the use of LLMs for data augmentation,aiming to generate domain-specific datasets to alleviate the scarcity of domain data.Experiments conducted on three domain-specific datasets demonstrate that our model outperforms existing comparative models in several aspects,with F1 scores exceeding the State of the Art models by 2%,1.6%,and 0.6%,respectively,validating the effectiveness and generalizability of our approach. 展开更多
关键词 relational triple extraction semantic interaction large language models data augmentation specific domains
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MLRT-UNet:An Efficient Multi-Level Relation Transformer Based U-Net for Thyroid Nodule Segmentation
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作者 Kaku Haribabu Prasath R Praveen Joe IR 《Computer Modeling in Engineering & Sciences》 2025年第4期413-448,共36页
Thyroid nodules,a common disorder in the endocrine system,require accurate segmentation in ultrasound images for effective diagnosis and treatment.However,achieving precise segmentation remains a challenge due to vari... Thyroid nodules,a common disorder in the endocrine system,require accurate segmentation in ultrasound images for effective diagnosis and treatment.However,achieving precise segmentation remains a challenge due to various factors,including scattering noise,low contrast,and limited resolution in ultrasound images.Although existing segmentation models have made progress,they still suffer from several limitations,such as high error rates,low generalizability,overfitting,limited feature learning capability,etc.To address these challenges,this paper proposes a Multi-level Relation Transformer-based U-Net(MLRT-UNet)to improve thyroid nodule segmentation.The MLRTUNet leverages a novel Relation Transformer,which processes images at multiple scales,overcoming the limitations of traditional encoding methods.This transformer integrates both local and global features effectively through selfattention and cross-attention units,capturing intricate relationships within the data.The approach also introduces a Co-operative Transformer Fusion(CTF)module to combine multi-scale features from different encoding layers,enhancing the model’s ability to capture complex patterns in the data.Furthermore,the Relation Transformer block enhances long-distance dependencies during the decoding process,improving segmentation accuracy.Experimental results showthat the MLRT-UNet achieves high segmentation accuracy,reaching 98.2% on the Digital Database Thyroid Image(DDT)dataset,97.8% on the Thyroid Nodule 3493(TG3K)dataset,and 98.2% on the Thyroid Nodule3K(TN3K)dataset.These findings demonstrate that the proposed method significantly enhances the accuracy of thyroid nodule segmentation,addressing the limitations of existing models. 展开更多
关键词 Thyroid nodules endocrine system multi-level relation transformer U-Net self-attention external attention co-operative transformer fusion thyroid nodules segmentation
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A Joint Entity Relation Extraction Model Based on Relation Semantic Template Automatically Constructed
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作者 Wei Liu Meijuan Yin +1 位作者 Jialong Zhang Lunchong Cui 《Computers, Materials & Continua》 SCIE EI 2024年第1期975-997,共23页
The joint entity relation extraction model which integrates the semantic information of relation is favored by relevant researchers because of its effectiveness in solving the overlapping of entities,and the method of... The joint entity relation extraction model which integrates the semantic information of relation is favored by relevant researchers because of its effectiveness in solving the overlapping of entities,and the method of defining the semantic template of relation manually is particularly prominent in the extraction effect because it can obtain the deep semantic information of relation.However,this method has some problems,such as relying on expert experience and poor portability.Inspired by the rule-based entity relation extraction method,this paper proposes a joint entity relation extraction model based on a relation semantic template automatically constructed,which is abbreviated as RSTAC.This model refines the extraction rules of relation semantic templates from relation corpus through dependency parsing and realizes the automatic construction of relation semantic templates.Based on the relation semantic template,the process of relation classification and triplet extraction is constrained,and finally,the entity relation triplet is obtained.The experimental results on the three major Chinese datasets of DuIE,SanWen,and FinRE showthat the RSTAC model successfully obtains rich deep semantics of relation,improves the extraction effect of entity relation triples,and the F1 scores are increased by an average of 0.96% compared with classical joint extraction models such as CasRel,TPLinker,and RFBFN. 展开更多
关键词 Natural language processing deep learning information extraction relation extraction relation semantic template
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A Study on Semantic Relations of“and”Used in Chinese EFL Learners’Narrative Writing
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作者 LI Cai-hong 《Journal of Literature and Art Studies》 2022年第11期1169-1174,共6页
Studies on conjunctions used by Chinese English as a Foreign Language(EFL)learners over the past ten years have focused mainly on the use of conjunctions in argumentative writing,and there is little empirical work on ... Studies on conjunctions used by Chinese English as a Foreign Language(EFL)learners over the past ten years have focused mainly on the use of conjunctions in argumentative writing,and there is little empirical work on conjunction“and”in narrative writing.The purpose of this paper is to explore the characteristics of the semantic relations of“and”used in the narrative writing of Chinese EFL learners from the perspective of text coherence.Through analysis of narrative writing of 29 sophomores,this study investigates the characteristics of semantic relations expressed by the conjunction“and”and the differences in the use of semantic relations of“and”between high-score and low-score writing.The results show different frequencies of the use of semantic relations of“and”.ELF learners prefer to use the term“and”to build progressive relation and parallel relation more than any other relation.Both high-score and low-score writing use a sizable number of“and”to build progressive relation and parallel relation,but high-score writing obviously contains more guiding relations and fewer supplementary relations.These findings have some pedagogical implications for teaching transitions. 展开更多
关键词 Cohesion Theory conjunction“and” ELF learners semantic relation
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The Application of Semantic Relations and Denotative and Connotative Meanings in Translation Practice
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作者 余相宜 《海外英语》 2013年第7X期145-147,共3页
Semantics,the study of meaning,is closely connected with translation,the practice of transferring meaning.The paper uses a lot of examples based on real translation practice to prove that semantics plays a very import... Semantics,the study of meaning,is closely connected with translation,the practice of transferring meaning.The paper uses a lot of examples based on real translation practice to prove that semantics plays a very important role in translation practice.Understanding and making good use of semantic relations,including synonymy,polysemy,homonymy and antonymy,are quite important for a translator to deal with some complicated semantic problems in translation practice.The paper also discusses the concept of denotative and connotative meanings,two basic types of meaning in Semantics.Denotation means the literal meaning of a word which is given in dictionaries;and connotation,the associative and suggestive meanings of a word in its context.Be cause of cultural difference,words with the same denotations may have totally different connotations,which is why the concept of denotation and connotation plays a very important role in English/Chinese translation.In order to translate a text into another language correctly,translator must totally understand the meaning of the original word,both denotative and connotative mean ing,and be aware of the potential connotations of the word in the target language. 展开更多
关键词 semantic relations denotative connotative translat
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Application of Matrix Method of Presenting Semantic Relations in Didactic Practice
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作者 Eva Lelakova Marta Lackova 《Psychology Research》 2015年第1期1-9,共9页
关键词 语义关系 应用程序 矩阵法 矩阵分析 语言学 可替代 组件化 词汇
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Parameter-driven Level of Detail Derivation Method for Semantic Building Facade Model
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作者 WANG Yuefeng JIAO Wei 《Journal of Geodesy and Geoinformation Science》 CSCD 2024年第3期57-75,共19页
The relentless progress in the research of geographic spatial data models and their application scenarios is propelling an unprecedented rich Level of Detail(LoD)in realistic 3D representation and smart cities.This pu... The relentless progress in the research of geographic spatial data models and their application scenarios is propelling an unprecedented rich Level of Detail(LoD)in realistic 3D representation and smart cities.This pursuit of rich details not only adds complexity to entity models but also poses significant computational challenges for model visualization and 3D GIS.This paper introduces a novel method for deriving multi-LOD models,which can enhance the efficiency of spatial computing in complex 3D building models.Firstly,we extract multiple facades from a 3D building model(LoD3)and convert them into individual semantic facade models.Through the utilization of the developed facade layout graph,each semantic facade model is then transformed into a parametric model.Furthermore,we explore the specification of geometric and semantic details in building facades and define three different LODs for facades,offering a unique expression.Finally,an innovative heuristic method is introduced to simplify the parameterized facade.Through rigorous experimentation and evaluation,the effectiveness of the proposed parameterization methodology in capturing complex geometric details,semantic richness,and topological relationships of 3D building models is demonstrated. 展开更多
关键词 3D building model multi-level of Detail(LoD) semantic facade model CITYGML 3D GIS
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The Exchange from Relational Schemas to XML Schemas Based on Semantic Constraints
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作者 YANG Chengsen SUN Jinguang 《Wuhan University Journal of Natural Sciences》 CAS 2008年第4期485-489,共5页
XML is the standard format for data exchange between inter-enterprise applications on the Internet. To facilitate data exchange, industry groups define public document type that specify the format of the XML data to b... XML is the standard format for data exchange between inter-enterprise applications on the Internet. To facilitate data exchange, industry groups define public document type that specify the format of the XML data to be exchanged between their applications. In this paper, we propose a new method to solve the problem of automating the conversion of relational data into XML. During the conversion, we considers not only the structure of relational schemas, but also semantic constraints such as inclusion dependencies during the translation--it takes as input a relational schema where multiple tables are interconnected through inclusion dependencies and converts it into an X-Schema. Finally, in order to validate our proposal, we present experimental results using real schemas. 展开更多
关键词 XML relational schemas semantic constraints inclusion dependencies
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Syntax-Enhanced Entity Relation Extraction with Complex Knowledge
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作者 Mingwen Bi Hefei Chen Zhenghong Yang 《Computers, Materials & Continua》 2025年第4期861-876,共16页
Entity relation extraction,a fundamental and essential task in natural language processing(NLP),has garnered significant attention over an extended period.,aiming to extract the core of semantic knowledge from unstruc... Entity relation extraction,a fundamental and essential task in natural language processing(NLP),has garnered significant attention over an extended period.,aiming to extract the core of semantic knowledge from unstructured text,i.e.,entities and the relations between them.At present,the main dilemma of Chinese entity relation extraction research lies in nested entities,relation overlap,and lack of entity relation interaction.This dilemma is particularly prominent in complex knowledge extraction tasks with high-density knowledge,imprecise syntactic structure,and lack of semantic roles.To address these challenges,this paper presents an innovative“character-level”Chinese part-of-speech(CN-POS)tagging approach and incorporates part-of-speech(POS)information into the pre-trained model,aiming to improve its semantic understanding and syntactic information processing capabilities.Additionally,A relation reference filling mechanism(RF)is proposed to enhance the semantic interaction between relations and entities,utilize relations to guide entity modeling,improve the boundary prediction ability of entity models for nested entity phenomena,and increase the cascading accuracy of entity-relation triples.Meanwhile,the“Queue”sub-task connection strategy is adopted to alleviate triplet cascading errors caused by overlapping relations,and a Syntax-enhanced entity relation extraction model(SE-RE)is constructed.The model showed excellent performance on the self-constructed E-commerce Product Information dataset(EPI)in this article.The results demonstrate that integrating POS enhancement into the pre-trained encoding model significantly boosts the performance of entity relation extraction models compared to baseline methods.Specifically,the F1-score fluctuation in subtasks caused by error accumulation was reduced by 3.21%,while the F1-score for entity-relation triplet extraction improved by 1.91%. 展开更多
关键词 Entity relation extraction complex knowledge syntax-enhanced semantic interaction pre-trained BERT
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Mechanisms underlying syntactic and semantic processing of Chinese simple sentences Evidence from event-related brain potentials
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作者 Huanhai Fang Ming Zhao 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第25期1937-1941,共5页
This study sought to test the processing of three types of sentences in Chinese, as correct sentences, semantic violation sentences, and sentences containing semantic and syntactic violations, based on the following s... This study sought to test the processing of three types of sentences in Chinese, as correct sentences, semantic violation sentences, and sentences containing semantic and syntactic violations, based on the following sentence pattern: "subject (noun) + yi/gang/zheng + predicate (verb)". Event-related potentials on the scalp were recorded using 32-channel electroencephalography. Compared with correct sentences, target words elicited an early left anterior negativity (N400) and a later positivity (P600) over frontal, central and temporal sites in sentences involving semantic violations. In addition, when sentences contained both semantic and syntactic violations, the target words elicited a greater N400 and P600 distributed in posterior brain areas. These results indicate that Chinese sentence comprehension involves covert grammar processes. 展开更多
关键词 CHINESE SYNTACTIC semantic event-related brain potentials processing mechanism
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Exploiting multi-context analysis in semantic image classification
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作者 田永鸿 黄铁军 高文 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第11期1268-1283,共16页
As the popularity of digital images is rapidly increasing on the Internet, research on technologies for semantic image classification has become an important research topic. However, the well-known content-based image... As the popularity of digital images is rapidly increasing on the Internet, research on technologies for semantic image classification has become an important research topic. However, the well-known content-based image classification methods do not overcome the so-called semantic gap problem in which low-level visual features cannot represent the high-level semantic content of images. Image classification using visual and textual information often performs poorly since the extracted textual features are often too limited to accurately represent the images. In this paper, we propose a semantic image classification ap- proach using multi-context analysis. For a given image, we model the relevant textual information as its multi-modal context, and regard the related images connected by hyperlinks as its link context. Two kinds of context analysis models, i.e., cross-modal correlation analysis and link-based correlation model, are used to capture the correlation among different modals of features and the topical dependency among images induced by the link structure. We propose a new collective classification model called relational support vector classifier (RSVC) based on the well-known Support Vector Machines (SVMs) and the link-based cor- relation model. Experiments showed that the proposed approach significantly improved classification accuracy over that of SVM classifiers using visual and/or textual features. 展开更多
关键词 Image classification Multi-context analysis Cross-modal correlation analysis Link-based correlation model Linkage semantic kernels relational support vector classifier
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Semantic Features and Applications in Translation of English Words in Pairs
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作者 LIN Shan-ling 《Sino-US English Teaching》 2011年第6期398-405,共8页
English words in pairs are a special form of English idioms, which have different kinds and are used widely. For English learners, words in pairs are one of the difficult points. This paper discusses their form patter... English words in pairs are a special form of English idioms, which have different kinds and are used widely. For English learners, words in pairs are one of the difficult points. This paper discusses their form patterns, semantic relations, grammatical functions, rhetoric features and their application in translation. Its purpose is to help learners understand and use them accurately and correctly so as to improve language expressing ability. 展开更多
关键词 words in pairs form patterns semantic relations grammatical functions rhetoric features application intranslation
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How Some Sense Relations Affect Language Use
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作者 Li Ying (Shandong Health School, Ji’nan, 250012,China) 《山东教育学院学报》 2002年第4期76-79,共4页
Language must make contact with the outside world.This contact is what we call meaning.The meaning of words forms part of human linguistic knowledge and therefore part of grammar.For foreign language teachers and lear... Language must make contact with the outside world.This contact is what we call meaning.The meaning of words forms part of human linguistic knowledge and therefore part of grammar.For foreign language teachers and learners,it is necessary to distinguish some lexical meanings in English,for it is these different sense relations that affect language use.This article analyzes the possible reasons which cause these changes in language use and aims at providing linguistic assistance for foreign language teaching and learning. 展开更多
关键词 词义 语法 英语教学 识用 同义词 语义学
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形义对应复合词法构式的建构与语义类型
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作者 孟凯 《汉语学习》 北大核心 2025年第2期74-83,共10页
形义对应复合词法构式是由形式相同的一个成分和常用义具有对应关系(主要是同义、反义或类义)的另一个成分构成的语序相同的词法构式组。形义对应复合词法构式可建构为五级构式网络。该网络的建构条件是复合词法构式之间的语义依存性,... 形义对应复合词法构式是由形式相同的一个成分和常用义具有对应关系(主要是同义、反义或类义)的另一个成分构成的语序相同的词法构式组。形义对应复合词法构式可建构为五级构式网络。该网络的建构条件是复合词法构式之间的语义依存性,源自普遍存在于汉语使用者认知中的语义聚合关系。形义对应复合词法构式形成两种语义类型:语义对应,来自于形义对应复合词法构式形成的本质要求,是其基本特征和主要表现;语义偏离即语义不对应,来自于构件的语义选择、构件间的结构关系或构体义的引申。形义对应复合词法构式是基于构式网络的词法构式互动的结果。 展开更多
关键词 复合词 词法构式 形义对应 语义依存性 语义聚合关系 语义类型
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电子病历中基于实体识别和共现分析的疾病间语义关系挖掘研究
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作者 熊回香 周明洁 《情报科学》 北大核心 2025年第6期14-27,共14页
【目的/意义】揭示电子病历中潜在疾病间语义关系,解决语义关系模糊问题。【方法/过程】本文构建了基于实体识别和共现分析的疾病间关系挖掘模型,并以开放电子病历数据集为例进行实证研究。在实体识别上,本文主要运用BERT-BiLSTM-CRF深... 【目的/意义】揭示电子病历中潜在疾病间语义关系,解决语义关系模糊问题。【方法/过程】本文构建了基于实体识别和共现分析的疾病间关系挖掘模型,并以开放电子病历数据集为例进行实证研究。在实体识别上,本文主要运用BERT-BiLSTM-CRF深度学习模型从电子病历中抽取疾病及相关信息,采用共现分析方法对疾病间语义关系进行量化,最后使用相似度计算和层次聚类挖掘疾病间语义关系。【结果/结论】用于命名实体识别的深度学习模型性能较好,在验证集上的F1值达到0.95,采用共现分析的方法能较好挖掘疾病间语义关系。【创新/局限】本文融合直接共现与间接共现,提出一种基于综合共现的方法。 展开更多
关键词 深度学习 语义关系挖掘 中文电子病历 命名实体识别 共现分析
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基于关系视角的竞赛众包创意智能筛选方法
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作者 张雪峰 洪勇 《新疆财经》 2025年第5期16-29,共14页
对于竞赛众包,如何快速有效地对数量较多的备选创意进行筛选是亟须解决的问题。文章基于创意关系视角,从新颖性和可行性两个方面衡量创意质量,并采取去除低质量创意和保留高质量创意的筛选策略。首先针对以文本形式描述的创意,采用隐含... 对于竞赛众包,如何快速有效地对数量较多的备选创意进行筛选是亟须解决的问题。文章基于创意关系视角,从新颖性和可行性两个方面衡量创意质量,并采取去除低质量创意和保留高质量创意的筛选策略。首先针对以文本形式描述的创意,采用隐含狄利克雷分布主题模型,按照创意之间的差异化程度(新颖性)将创意划分为多个不同的主题;其次采用杰卡德系数计算方法构建每个主题及其所包含的全部创意的语义网络,并转化为对应的累积分布,进而通过Kolmogorov-Smirnov统计量度量网络之间的距离;最后对每个主题中的创意按照可行性的高低(网络距离的大小)进行排序,从而为创意筛选提供依据。进一步地,将此方法用于筛选3个竞赛众包中的创意,结果表明该方法在识别低质量创意中的精确率较高,在识别高质量创意中的召回率较高。相较于常见的基于文本长度、大众评价、SBERT模型的筛选方法,该方法在筛选的精确率和召回率上均表现更好。 展开更多
关键词 竞赛众包 创意筛选 关系视角 语义网络
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基于图网络的遥感地物关系表达与推理的地表异常检测 被引量:1
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作者 刘思琪 高智 +4 位作者 陈泊安 路遥 朱军 李衍璋 王桥 《电子与信息学报》 北大核心 2025年第6期1690-1703,共14页
遥感地物间的语义关系可以表征地物间的相互影响与结构信息,对地表的灾害检测与应急响应具有重要意义。然而,现有的遥感地物关系提取方法多依赖于目标检测,定位精度有限,且关系预测网络主要局限于注意力机制、卷积网络,难以有效建模复... 遥感地物间的语义关系可以表征地物间的相互影响与结构信息,对地表的灾害检测与应急响应具有重要意义。然而,现有的遥感地物关系提取方法多依赖于目标检测,定位精度有限,且关系预测网络主要局限于注意力机制、卷积网络,难以有效建模复杂拓扑关系。此外,公开规范的遥感地物关系数据集的缺乏也进一步制约了该领域的发展。为了解决上述问题,该文建立了遥感地物语义关系数据集,并采用了一种基于图神经网络的关系预测模型,准确提取遥感场景中蕴含的地物关系。具体而言,首先针对地物实例定义了遥感地物关系描述体系,结合地物类别和拓扑信息标注地物间的语义关系,构建了遥感地物语义关系数据集。其次,引入先进的图神经网络模型进行关系预测,通过子图采样和超参数优化,有效提升了模型在遥感场景下的性能。通过上述方法,该文建立了一个小型的遥感地物语义关系数据集,探索了图神经网络在遥感地表异常场景中地物关系提取的应用。在遥感地物关系描述数据集上进行的实验结果表明,模型不仅在验证集的评估指标中表现出较强的竞争力,还在灾害异常场景中的实验中检测到灾害前后地物关系的显著变化,加强了对灾害场景地表异常的理解能力。 展开更多
关键词 图神经网络 遥感影像解译 语义关系 关系预测 拓扑关系
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集成空间数据引擎和图数据库的复杂地理时空语义建模研究 被引量:2
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作者 岳梓晨 钟少波 梅新 《地球信息科学学报》 北大核心 2025年第6期1289-1304,共16页
【目的】知识图谱作为一种融合多模态数据源的前沿技术,在GIS领域获得广泛关注。知识图谱主要通过图数据库构建。然而,目前主流的图数据库对地理时空数据的组织和分析仍面临挑战。【方法】为了解决这一问题,本文提出了一种桥接图数据库... 【目的】知识图谱作为一种融合多模态数据源的前沿技术,在GIS领域获得广泛关注。知识图谱主要通过图数据库构建。然而,目前主流的图数据库对地理时空数据的组织和分析仍面临挑战。【方法】为了解决这一问题,本文提出了一种桥接图数据库和空间数据引擎的时空语义建模与查询优化方法。该方法在图数据库中将地理实体存储为占位符节点(仅保留映射ID),并与时空索引节点(时间树、Geohash编码)建立关联,以增强时空聚合能力。同时,在关系数据库中存储完整的地理时空对象,并采用表分区策略优化检索效率。该方法通过统一标识符和JDBC实现跨数据库地理实体的路由映射,当用户调用图数据库中预注册的时空函数时,查询重写器基于实体标识符将图查询转换为SQL语句,并下推至关系数据库处理,随后将结果反馈至图查询流程。此外,引入两阶段提交协议保障异构数据库的数据同步性。【结果】本文通过集成Neo4j和PostGIS实现了该方法的原型系统,并基于深圳市多源时空数据集(包含出租车轨迹、共享单车轨迹、路网、POI及遥感影像),对不同规模数据进行查询和存储效率实验。结果表明:相较于主流图数据库系统(Neo4j、GraphDB),本方法在地理时空查询中显著提升性能,尤其在复杂计算场景下响应时间可缩短1~2个数量级,并支持原生图数据库无法实现的栅格计算;通过轻量化图节点和PostGIS数据压缩,存储空间减少约3~5倍。相较于虚拟知识图系统(Ontop),本方法在空间查询和存储消耗上差异较小,但在大规模时空查询中响应时间显著缩短。【结论】相较于现有方法,本文方法可直接利用现有图数据库构建实体化时空知识图,提升了地理时空知识图的建模灵活性和查询效率,且支持用户自定义扩展地理时空函数库,为知识图谱中地理时空数据的高效管理和分析提供了新的思路。 展开更多
关键词 图数据库 关系数据库 时空语义 空间数据引擎 查询优化 知识图谱 时空索引
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基于大语言模型全流程微调的叙词表等级关系构建研究 被引量:1
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作者 李泽宇 刘伟 《情报理论与实践》 北大核心 2025年第4期152-162,共11页
[目的/意义]随着知识组织系统运作环境的变化,知识组织的重要性不断提升,为突破传统叙词表构建及应用困境,结合最新大语言模型技术探索叙词表构建新范式。[方法/过程]从叙词表自身特征及其构建思路入手,采用继续预训练、监督微调和强化... [目的/意义]随着知识组织系统运作环境的变化,知识组织的重要性不断提升,为突破传统叙词表构建及应用困境,结合最新大语言模型技术探索叙词表构建新范式。[方法/过程]从叙词表自身特征及其构建思路入手,采用继续预训练、监督微调和强化学习的全流程微调,结合本地知识库的方案,对大语言模型进行微调训练,并基于“量子科技”领域和“理论力学”领域进行实证。[结果/结论]实证发现,经过继续预训练、“多策略数据处理微调方案”和RLHF的微调方案表现更优。其中,对于“理论力学”领域的已有词表等级关系构建准确度高达89.06%,“量子科技”新兴领域词表等级关系构建准确度为63.02%。这表明,本方案可以实现已有词表等级关系的构建,且在新领域词表等级关系的构建中表现良好,具备一定可行性,能为新领域叙词表构建提供参考。 展开更多
关键词 叙词表 大语言模型 等级关系 知识组织系统 语义关系
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