共查询到20条相似文献，搜索用时 31 毫秒
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《Journal of Informetrics》2014,8(3):594-605
This study presents a unique approach in investigating the knowledge diffusion structure for the field of data quality through an analysis of the main paths. We study a dataset of 1880 papers to explore the knowledge diffusion path, using citation data to build the citation network. The main paths are then investigated and visualized via social network analysis. This paper takes three different main path analyses, namely local, global, and key-route, to depict the knowledge diffusion path and additionally implements the g-index and h-index to evaluate the most important journals and researchers in the data quality domain. 相似文献
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[目的/意义]潜在狄利克雷分布(Latent Dirichlet Allocation,LDA)在科技情报分析中用来发现学科主题、挖掘研究热点以及预测研究趋势等。对常见的科学文献文本语料库(关键词、摘要、关键词+摘要)进行LDA主题抽取效果的评价,以揭示不同语料库的主题抽取效果,提高LDA在科技情报分析中的应用效果。[方法/过程]对上述3种语料库下的LDA主题模型进行对比研究,采用基于查全率、查准率、F值以及信息熵的定量分析和基于主题抽取的广度和主题粒度的定性分析相结合的方法对主题抽取效果进行评价。[结果/结论]通过国内风能领域的科学文献数据实证研究发现,无论是从定量分析还是从定性分析来看,摘要和关键词+摘要作为语料的LDA主题抽取的效果均优于关键词作为语料的LDA主题抽取效果,并且前者在主题抽取的广度方面表现更好,而后者抽取的主题粒度更细。 相似文献
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以知识管理领域为样本,利用Pajek集成的主路径算法提取从ISI WoS检索的样本引文数据的主路径发现:三种主路径算法功能相同。对比样本领域的主路径元素间的完整引用关系网络与结构洞发现:二者在结构上完全相同,差异仅在于弧线线值,意味着主路径具有网络结构洞功能。基于全局中心结构洞与自我中心结构的进一步研究发现:主路径元素的结构洞功能与功能大小差异显著。 相似文献
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科学引文网络反映了科学知识的动态演化,作为一个复杂的网络系统已得到广泛研究。针对引文网络中主题不明确和热点问题不易跟踪的问题,提出了引文网络中的舆论评价计算方法和网络社区主题提取与表示方法。首先采用正则表达式和模板匹配方法提取元数据;并计算文献作者对参考文献的舆论评价,建立带有舆论评价权值的文献引用网络,并对网络中的突现语义进行描述;然后以此网络结构为基础,结合信息熵和网络中文献重要性权重改进TDIDF算法,计算得到每个社区主题的关键词概率描述,从而得到社区主题。本文的方法和实验对解释引文网络的演化、社区主题发现、文献的共享等有借鉴意义。 相似文献
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[目的/意义] 概率主题模型算法在不断得到改进与扩展，本文对国内外已有的利用引文构建的主题模型进行研究，分析和对比不同模型的生成过程与算法，并探讨利用引文构建的主题模型在科技文本分析中的应用与可扩展的研究方向。[方法/过程] 通过Web of Science数据库和CNKI数据库获取国内外利用引文构建主题模型的相关文献，经人工判读后筛选出具有代表性的文献，对这些文献中利用引文构建的主题模型，从建模思想、生成过程、参数估计与推断算法等方面进行对比与分析。[结果/结论] 目前国内外利用引文构建的主题模型主要包括研究主题与引文分布的主题模型、研究被引与施引主题间关系的主题模型，以及基于引用内容的引用主题模型；主题模型中引入引文信息后，能够获得更完整的主题内容和特定主题下的重要文献，并可识别施引文献和被引文献之间主题间的关系及影响；已有的模型多集中在概率潜在语义分析（Probabilistic Latent Semantic Analysis，PLSA）和潜在狄利克雷分配（Latent Dirichlet Allocation，LDA）主题模型基础上进行扩展。未来可扩展研究引入引用内容的主题模型、模型的性能优化和评价方法、模型的应用研究等。 相似文献
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��[Purpose/significance] This paper proposes the identification of the core research topics and their evolution path visualization methods, in order to provide reference for the field subject evolution analysis research, which has certain significance for revealing the evolution characteristics and development laws of the core topics.[Method/process] Using the LDA model for topic recognition and combining multi-dimensional scaling analysis and visualization techniques to map LDA topic recognition results to two-dimensional space. The topic similarity algorithm was used to detect the association between adjacent time topics, a new visual display method was proposed. We constructed cross-evolution paths of different types of research topics to reveal the dynamic changes of core topics and secondary topics in the evolution process.[Result/conclusion] Taking the medical health information field in China as an example, the research results show that the core research topics in the field of medical and health information in China mainly include electronic health records and Internet medical treatment. Among them, core themes such as health management and smart medical treatment show a good development trend. 相似文献
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《Journal of Informetrics》2022,16(3):101317
This research proposes a new approach that considers citation relevance in main path analysis (MPA). Traditional MPA assumes that all citations have equal weight, but in practice treating every citation equally may not find the main paths that truthfully reflect the knowledge flow in a target science field. To address the issue, this study suggests taking the level of relevance among documents into consideration. For demonstration purposes, the level of relevance is determined by similarity in both citation structure and key phrases among documents. The approach not only achieves convergence of development trajectories, but also helps frame the topics on the main paths to a specific concept from a wide range of research domains. This study takes health interoperability fields as the demonstration case to show the effects of converging the trajectories toward a target domain. 相似文献
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[目的/意义]以汽车论坛例，提出一种针对专业社交媒体文本的主题知识元抽取方法。[方法/过程]首先，通过LDA模型提取出汽车论坛中文本的主题，并进行去重，形成主题列表；其次，基于融合主题特征的深度学习模型T-LSTM模型构建适于汽车论坛本文的情感分析模型；然后，通过计算各词汇在图模型TextRank中的重要性与各词汇的Word2Vec主题相似度，抽取情感关键词与关键句，用于对文本主题与情感倾向的解释与补充；最后，对上述方法进行集成，输出结构化的主题知识元。[结果/结论]实验结果中，抽取得到的主题知识元合格率达到69.1%，表明本文提出的主题知识元抽取方法，能够围绕知识主题较为准确地抽取知识元，实现知识的结构化转换。 相似文献
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《Journal of Informetrics》2019,13(4):100977
Main path analysis is a popular method for extracting the backbone of scientific evolution from a (paper) citation network. The first and core step of main path analysis, called search path counting, is to weight citation arcs by the number of scientific influence paths from old to new papers. Search path counting shows high potential in scientific impact evaluation due to its semantic similarity to the meaning of scientific impact indicator, i.e. how many papers are influenced to what extent. In addition, the algorithmic idea of search path counting also resembles many known indirect citation impact indicators. Inspired by the above observations, this paper presents the FSPC (Forward Search Path Count) framework as an alternative scientific impact indicator based on indirect citations. Two critical assumptions are made to ensure the effectiveness of FSPC. First, knowledge decay is introduced to weight scientific influence paths in decreasing order of length. Second, path capping is introduced to mimic human literature search and citing behavior. By experiments on two well-studied datasets against two carefully created gold standard sets of papers, we have demonstrated that FSPC is able to achieve surprisingly good performance in not only recognizing high-impact papers but also identifying undercited papers. 相似文献
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We propose two new indices that are able to measure a scientific researcher's overall influence and the level of his/her works’ association with the mainstream research subjects within a scientific field. These two new measures – the total influence index and the mainstream index – differ from traditional performance measures such as the simple citation count and the h-index in that they take into account the indirect influence of an author's work. Indirect influence describes a scientific publication's impact upon subsequent works that do not reference it directly. The two measures capture indirect influence information from the knowledge emanating paths embedded in the citation network of a target scientific field. We take the Hirsch index, data envelopment analysis, and lithium iron phosphate battery technology field to examine the characteristics of these two measures. The results show that the total influence index favors earlier researchers and successfully highlights those researchers who have made crucial contributions to the target scientific field. The mainstream index, in addition to underlining total influence, also spotlights active researchers who enter into a scientific field in a later development stage. In summary, these two new measures are valuable complements to traditional scientific performance measures. 相似文献
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［目的/意义］ 开展面向特定技术领域的技术演化路径识别,有助于梳理技术发展脉络进而对未来的技术发展方向做出合理预测,对识别科技优先领域、合理配置科技资源具有重要意义。［方法/过程］ 在梳理技术演化与技术演化路径的相关内涵的基础上,简要辨析了技术演化路径相关概念;进而从专利文献中的不同信息出发,从专利分类、专利引文、专利文本以及融合多种字段信息来总结技术演化路径识别研究的主要进展,并进一步归纳出该主题的整体发展趋势。［结果/结论］ 技术演化路径识别研究主要趋势包括：数据来源从单一数据转向多源异构数据融合,研究方法从注重定量转向定性与定量相结合,关注视角从历史演化路径识别转向未来演化路径预测,应用场景由一般性技术到颠覆性技术转变。 相似文献
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《Journal of Informetrics》2022,16(2):101281
Main Path Analysis (MPA) is widely used to trace the developmental trajectory of a technological field through a citation network. The citation-based traversal weight is usually utilized to cherry-pick the most significant path. However, the theme of documents along a main path may not be so coherent, and it is very possible to miss the main paths of significant sub-fields overall in a domain. Furthermore, the global path search algorithm in conventional MPA also suffers from high space complexity due to the exhaustive strategy. To address these limitations, a new method, named as semantic MPA (sMPA), is proposed by leveraging semantic information in two steps of candidate path generation and main path selection. In the meanwhile, the resulting source code can be freely accessed. To demonstrate the advantages of our method, extensive experiments are conducted on a patent dataset pertaining to lithium-ion battery in electric vehicle. Experimental results show that our sMPA is capable of discovering more knowledge flows from important sub-fields, and improving the topical coherence of candidate paths as well. 相似文献
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[目的/意义]无处不在的网络舆情信息深深影响甚至误导网络受众,探讨揭示网络舆情观点的方法,旨在拓展用户的认知深度和广度,提高大众对舆论的辨识能力。[方法/过程]从技术上对比分析观点提取方法间的差异,从认知上阐释网络舆论平台的群体智慧和受众个体的认知过程,进而明确LDA主题模型提取舆情观点的优势及路径。[结果/结论]结合舆论主题和情感因素,基于LDA的网络舆情观点提取,可从海量评论中判定深度评论,摘取主要观点,借助群众智慧,有效拓展个体思想和认知,为从大规模舆情中有序呈现受众观点提供新路径,也为舆情监测与疏导提供切实的依据。 相似文献
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基于被引次数的引文分析无法直接揭示论文的研究内容,利用关键词或从标题、摘要和全文中抽取的主题词很难客观反映论文的被引原因。本文以碳纳米管纤维研究领域的高被引论文为研究对象进行引文内容抽取和主题识别,经人工判读验证：基于引文内容分析的高被引论文识别的核心主题能够较好地揭示高被引论文的被引原因（引用动机）,而且与论文的研究内容相符合;与基于全文、基于标题和摘要的主题识别相比,在引文内容分析基础上识别的主题具有更好的主题代表性,能够有效揭示被引文献的研究内容,是对原文相关信息的重要补充。本文的实验表明基于引文内容分析的高被引论文主题识别是可行而且有效的。图4。表4。参考文献31。 相似文献
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[目的/意义] 在科学研究中,从不同来源的科技文献中识别挖掘科研热点对于开展科研工作具有指导意义。旨在通过本研究提出的模型方法,快速准确地识别蕴含在多源文本中的热点主题,为科研创新提供支撑服务。[方法/过程] 提出一种基于LDA2vec模型的多源文本下科研热点识别的方法并针对科研热点识别构建模型,该方法融合LDA主题模型对隐含语义挖掘的优势和Word2Vec词向量模型对于上下文关系把握的优势。以机器学习领域的科技文献为例,利用模型困惑度和主题一致性两个指标对LDA2vec的在本领域应用的可行性和有效性进行验证,并与LDA的主题提取效果进行对比。[结果/结论] 实验结果表明,提出的方法在面对多源数据情况下,进行科研热点识别挖掘是可行的,且在一定程度上有效果的提升,对利用单一数据源进行主题分析的不足进行补充,对多数据源融合的实践应用进行丰富。 相似文献
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[目的/意义]随着信息资源在数量和种类上的急剧增长,学科间的交叉融合不断涌现,快速主动地从海量信息资源中识别和判断研究主题的发展演化是实现科技创新的基础。[方法/过程]在相关理论调研的基础上,结合医学领域的资源特点,提出一种基于LDA模型的主题演化探测模型和相应的流程步骤。主要步骤包括医学主题词抽取、主题识别、主题关联、关键主题识别、关键主题的演化主路径识别、演化主路径上主题分裂、融合事件识别,实现深度、细致的主题演化分析。[结果/结论]选用乳腺癌治疗研究文献为实验案例,对判断模型进行试验并对结果进行分析验证,证实提出的技术方法具有一定的可靠性。 相似文献
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[目的/意义] 跨学科研究已成为现代科学创新研究的重要范式和必然趋势，探究跨学科领域中学科的发展模式与演化路径，对于揭示跨学科领域形成与发展的动态过程具有重要意义。[方法/过程] 以眼动追踪（Eye Tracking，ET）领域为例，对文献引文关系进行提取与学科标注，构建文献和学科层面的引文关系网络；计算各学科的他引比率、他被引比率和普赖斯指数，从宏观层面分析ET领域中主要学科的跨学科发展模式；考察不同阶段内部及不同阶段之间的学科引证关系，探究不同阶段各学科在跨学科发展过程中的关系结构与角色演变；基于引文的中介中心度识别连接不同学科关系的重要文献，考察重要文献、高被引文献以及参考文献之间的引文关系，从微观层面揭示ET领域发展的具体演化路径。[结果/结论] ET领域发展经历潜伏期、发展期和成熟期三个阶段，并呈现独立型、交叉型和学习型三种学科发展模式；各学科之间的引证关系随阶段变化逐渐紧密且分布逐渐均匀，神经学、心理学和临床医学在跨学科发展和知识输出方面处于核心地位；ET领域纵向发展表现为独立型学科的基础理论创新，横向发展表现为3种类型学科的深度融合，并呈现出"独立-线性-网状"的发展路径。 相似文献