首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
[目的/意义]运用深度学习技术,提出结合时间和空间特征的测度(速度、覆盖度和迂回度)方法,用于量化学者研究主题演化,从而为基于内容的学者评价提供量化依据。[方法/过程]提出三维指标框架,其中速度反映作者改变研究主题快慢的平均程度,覆盖度反映作者研究内容所覆盖的主题广度,迂回度反映作者研究路径的曲折性。使用微软学术数据集中计算机科学的作者进行实证研究,并考察学者研究主题演化的三维测度和学者学术影响力和生产力的关系。[结果/结论] 实证研究结果显示,覆盖度与总被引量和总发文量的关系为单调递减,这一特征说明聚焦于特定研究主题较为深入的作者,其发文量和影响力都较大。作者研究主题演化的"速度"和"迂回度"与总被引量、总发文量都存在先增加后减少的倒U型关系。所提出的多维度指标框架不仅可在理论上丰富科学计量学对于学者研究主题转移演化及其机制的理解,而且结合深度学习模型提出了问题的解决思路。  相似文献   

2.
[目的/意义] 探讨不同学科分类体系在机构科研影响力评价中的差异及对评价结果的影响。[方法/过程] 以Incites数据库为数据来源,选择5种分类体系、8种分类方案。首先对14 955个机构不同分类方案下的学科标准化引文影响力(Category Normalized Citation Impact,CNCI)进行相关性分析,考察不同分类体系下评价结果的整体相似性。然后以国内双一流建设中的36所高校为例,比较和分析不同分类方案下机构CNCI值的变化情况及差异产生的具体原因,研究分类体系对个体机构评价的影响。[结果/结论] 不同学科分类方案下得到的CNCI值相关性显著(最低相关性达到0.85),即不同分类体系得到的整体评价结果具有较高的相似度。但是不同分类体系下的评价结果也存在聚类特征,OECD、ESI、SCADC、CT1相互之间相关系数高、结果更相近,WoS、CT2和CT3评价结果更接近,分类体系的粒度是决定评价结果的重要因素。36所高校在不同的分类体系下评价结果的整体相关性较高,但个别高校CNCI值变化较大,特别是在热点主题上有突出发文的机构。评价结果的巨大差异其根本原因是论文划分到不同类目中,不同类目下的引用基准值不同。在评价过程中更加推荐粒度较细的分类体系,减少热点主题等对引用基准值的影响。  相似文献   

3.
One important reason for the use of field categorization in bibliometrics is the necessity to make citation impact of papers published in different scientific fields comparable with each other. Raw citations are normalized by using field-categorization schemes to achieve comparable citation scores. There are different approaches to field categorization available. They can be broadly classified as intellectual and algorithmic approaches. A paper-based algorithmically constructed classification system (ACCS) was proposed which is based on citation relations. Using a few ACCS field-specific clusters, we investigate the discriminatory power of the ACCS. The micro study focusses on the topic ‘overall water splitting’ and related topics. The first part of the study investigates intellectually whether the ACCS is able to identify papers on overall water splitting reliably and validly. Next, we compare the ACCS with (1) a paper-based intellectual (INSPEC) classification and (2) a journal-based intellectual classification (Web of Science, WoS, subject categories). In the last part of our case study, we compare the average number of citations in selected ACCS clusters (on overall water splitting and related topics) with the average citation count of publications in WoS subject categories related to these clusters. The results of this micro study question the discriminatory power of the ACCS. We recommend larger follow-up studies on broad datasets.  相似文献   

4.
《Journal of Informetrics》2019,13(2):695-707
Twitter accounts have already been used in many scientometric studies, but the meaningfulness of the data for societal impact measurements in research evaluation has been questioned. Earlier research focused on social media counts and neglected the interactive nature of the data. We explore a new network approach based on Twitter data in which we compare author keywords to hashtags as indicators of topics. We analyze the topics of tweeted publications and compare them with the topics of all publications (tweeted and not tweeted). Our exploratory study is based on a comprehensive publication set of climate change research. We are interested in whether Twitter data are able to reveal topics of public discussions which can be separated from research-focused topics. We find that the most tweeted topics regarding climate change research focus on the consequences of climate change for humans. Twitter users are interested in climate change publications which forecast effects of a changing climate on the environment and to adaptation, mitigation and management issues rather than in the methodology of climate-change research and causes of climate change. Our results indicate that publications using scientific jargon are less likely to be tweeted than publications using more general keywords. Twitter networks seem to be able to visualize public discussions about specific topics.  相似文献   

5.
The purpose of this exploratory study is to review scholarly publications and assess egovernment research efforts as a field of study specific to the United States e-government environment. Study results reveal that researchers who focus on the U.S. e-government environment assess specific e-government topics at the federal, state, and local levels; however, there are gaps in the research efforts by topic areas and across different levels of government, which indicate opportunities for future areas of research. Results also find that a multitude of methodology approaches are used to assess e-government. Issues, however, exist that include lack of or weak presentations of methodologies in publications, few studies include multi-method evaluation approaches for data collection and analysis efforts, and few studies take a theory-based approach to understanding the U.S. e-government environment.  相似文献   

6.
[目的/意义]研究前沿的准确判断是国家宏观层面的战略需求,文献计量学作为一种定量研究方法广泛应用于科学主题探测和研究前沿识别中。[方法/过程]梳理研究前沿主题探测的发展历程和方法模型,引入全域微观模型的概念,详细介绍SciVal模块采用的主题创建方法,包括直接引用文献聚类、关键词主题命名和研究前沿遴选的主题显著性算法,并对SciVal创建的9.6万个主题和遴选出的前1%的研究前沿主题的特征进行实证分析。[结果/结论]全域微观模型可以同时一次识别整个科学领域的所有主题,但不同学科在研究前沿上表现存在差异,不能把主题显著性简单等同为重要性;主题论文数量与主题排名之间存在中度相关性;自动抽取的关键词术语从学科领域层和独特性上命名和描述主题;石墨烯相关前沿主题的演变趋势分析可以用于发现关键节点和新兴主题。  相似文献   

7.
乔建忠 《图书情报工作》2013,57(14):114-120
针对主题爬行技术中的单一分类算法在面对多主题Web抓取和分类需求时泛化能力不强的局限,设计一种利用多种强分类算法形成的分类器组合,主题爬行器根据当前主题任务在线评估并为分类器排名,从中选择最优分类器分类的策略,并开展在多个主题抓取任务下的分类实验,比较每种分类算法的准确率和组合后的平均分类准确率以及对分类效率等评价指标的综合分析,结果证明该策略对领域局域性有所克服,普适性较强。  相似文献   

8.
[目的/意义] 学科主题演化研究有助于掌握学科发展现状、研究热点、研究前沿和发展趋势等情况,是进行科技创新的基础,是面向科技创新的重要研究方向。[方法/过程] 提出一种语义分类的学科主题演化分析方法:将关键词分为研究问题、研究方法和研究技术3类,构建不同语义分类的共词网络;然后基于Fast Unfolding社区发现算法识别具有语义特征的社区(主题);利用相似度算法计算相邻子时期主题间的相似度,构建学科主题演化图谱,以分析某学科领域研究问题、研究方法和研究技术的变化,实现深度、细致的学科主题演化分析。[结果/结论] 通过对2012-2015年CNKI数据库收录的我国大数据研究领域相关论文数据的处理分析,证明该方法的准确性和有效性。  相似文献   

9.
[目的/意义]主题排序不仅是信息检索、信息组织研究的基础性问题,也是图书馆学科服务的重要工作,对学科领域研究主题进行有效排序能够帮助科研人员和科研管理部门有效把握学科领域的研究态势,准确定位科研方向,快速做出科研决策。[方法/过程]基于趋势分析提出一种学科研究主题优先级排序算法。首先,在主题提取的基础上,根据发文趋势和引文趋势将每个研究主题按研究等级分为贫乏主题、热点主题、冷点主题、过热主题4个子类。然后,分别对各子类下的主题词进行优先级排序。[结果/结论]在情报学领域的实验表明:本文提出的优先级排序算法能够全方位、细粒度、深层次地展示学科领域研究主题的发展等级,该方法可为从时间维度实现动态情报分析提供新的视角。  相似文献   

10.
[目的/意义] 根据基金项目数据的特点,提出基于基金项目数据的研究前沿主题探测方法,以期识别出前瞻价值更高的研究前沿,为研究前沿识别相关研究提供借鉴思路。[方法/过程] 首先,基于PLDA模型识别蕴含在基金项目文本中的研究主题;然后基于主题-文档矩阵建立主题和基金项目文档的映射关系,在此基础上,利用主题的资助时间、资助金额和中心性指标进行研究前沿主题探测,从而识别出值得关注的研究前沿主题;最后,利用主题演化可视化分析方法,对研究前沿主题进行演化分析,以预测其发展趋势。[结果/结论] 研究结果表明,该方法可以根据基金项目数据的特点识别出蕴含在其中的研究前沿主题,并且能够分析研究前沿主题的分裂、融合等演化过程。  相似文献   

11.
Research topic studies have gained popularity in many disciplines, including library and information science (LIS). However, the lack of representation of library science and librarianship in literature indicates a research bias due to the preset methodology parameters, which are commonly based on impact factor scores in the Journal Citation Report of Thomson Reuters. In research, the authors utilize an improved selection criterion of journals and author-supplied keyword clustering and analysis technique to study the most recent ten years of LIS journal publications. This article presents a clear picture of popular research topics in seminal literature to help practicing librarians and library science scholars gain a better understanding and considerable prediction on the research trends in the LIS field.  相似文献   

12.
Research topics and research communities are not disconnected from each other: communities and topics are interwoven and co-evolving. Yet, scientometric evaluations of topics and communities have been conducted independently and synchronically, with researchers often relying on homogeneous unit of analysis, such as authors, journals, institutions, or topics. Therefore, new methods are warranted that examine the dynamic relationship between topics and communities. This paper examines how research topics are mixed and matched in evolving research communities by using a hybrid approach which integrates both topic identification and community detection techniques. Using a data set on information retrieval (IR) publications, two layers of enriched information are constructed and contrasted: one is the communities detected through the topology of coauthorship network and the other is the topics of the communities detected through the topic model. We find evidence to support the assumption that IR communities and topics are interwoven and co-evolving, and topics can be used to understand the dynamics of community structures. We recommend the use of the hybrid approach to study the dynamic interactions of topics and communities.  相似文献   

13.
Dynamic development is an intrinsic characteristic of research topics. To study this, this paper proposes two sets of topic attributes to examine topic dynamic characteristics: topic continuity and topic popularity. Topic continuity comprises six attributes: steady, concentrating, diluting, sporadic, transforming, and emerging topics; topic popularity comprises three attributes: rising, declining, and fluctuating topics. These attributes are applied to a data set on library and information science publications during the past 11 years (2001–2011). Results show that topics on “web information retrieval”, “citation and bibliometrics”, “system and technology”, and “health science” have the highest average popularity; topics on “h-index”, “online communities”, “data preservation”, “social media”, and “web analysis” are increasingly becoming popular in library and information science.  相似文献   

14.
[目的/意义] 基于社交媒体,探索突发事件信息生命周期中不同利益相关者的动态分类及其关注主题的演变规律,为更精准的危机信息监测与动态决策提供依据。[方法/过程] 以特定危机事件的事实文本数据为来源,以利益相关者理论和动态主题模型为指导,构建三维动态主题演化模型以对社交媒体危机事件中不同利益相关者的分类与话题关注进行主题挖掘。其中包括时间粒度划分、利益相关者的定量评估、基于时间和主体的危机主题观点识别与刻画,并利用可视化工具对该动态趋势进行表征。[结果/结论] 基于三维动态主题演化模型,利益相关者的组成与分类在不同阶段中具有明显的差异性,同时其关注主题与行为特征也体现出不同的偏好性和动态差异性。危机主体的动态与危机主题的动态有效结合,能够更加全面地表达舆情传播的特点和规律。  相似文献   

15.
分类搜索引擎类目体系研究   总被引:49,自引:0,他引:49  
论述分类搜索引擎类目结构的编制依据、大类结构、类目体系的特点等;对存在的问题展开讨论。  相似文献   

16.
This paper introduces a new approach to describe the spread of research topics across disciplines using epidemic models. The approach is based on applying individual-based models from mathematical epidemiology to the diffusion of a research topic over a contact network that represents knowledge flows over the map of science—as obtained from citations between ISI Subject Categories. Using research publications on the protein class kinesin as a case study, we report a better fit between model and empirical data when using the citation-based contact network. Incubation periods on the order of 4–15.5 years support the view that, whilst research topics may grow very quickly, they face difficulties to overcome disciplinary boundaries.  相似文献   

17.
Identifying research fronts is an essential aspect of promoting scientific development. Many researchers choose their research directions and topics by analyzing their field's current research fronts. Many previous researchers have used academic papers or patents to identify research fronts; however, this is potentially outdated and reduces the prospective value of the research front detection. Considering this, this work proposes adapted indicators to conduct research front topic detection based on research grant data, which aims to identify research front topics and forecast trends using path analysis. First, research topics were identified using topic modeling, and then the mapping relations from topics to both fund projects and cross-domain categories were built. Then, research front topics were detected by multi-dimensional measurements, and the evolution of research topics was analyzed using topic evolution visualization to predict development trends. Finally, the Brillouin index was used to measure the cross-domain degree. Our method was evaluated using a dataset from the field of health informatics and was shown to be effective in research front identification. We found that the proposed adapted indicators were informative in identifying the evolutional trends in the health informatics field. In addition, research grants with higher cross-domain degrees are more likely to receive a high amount of funding.  相似文献   

18.
[目的/意义] 基于主题关联相似度揭示主题汇聚及变异过程,识别学科交叉主题及交叉模式,归纳学科主题的演化趋势及演化路径模式。[方法/过程] 获取情报学学科科研论文的高频主题词,构造主题词共词矩阵,利用网络社区演化分析工具生成学科主题演化网络图,结合指标数据对学科主题演化过程进行分析。[结果/结论] 总体上看,情报学学科的研究主题虽然在反复地变化,但核心主题一直存在;扩张、收缩和合并是研究主题最普遍的变化态势,分裂现象较少,产生和消亡现象存在;有3条特定社区演化轨迹清晰地贯穿始终,活跃度相对稳定,反映了3类核心研究主题;3类核心研究主题的演化路径呈现出升华吸纳、共融迭新和辐射推进3种演化模式。研究结果显示,基于主题关联学科主题演化路径的多模式识别方法既能从宏观层面呈现学科主题演化形式,也能从微观层面分析学科主题交叉模式,结合二者可揭示学科主题的继承或创新,预测学科交叉主题的发展方向。  相似文献   

19.
As the representative of prominent scientists, understanding the Nobel laureates’ research patterns throughout their careers are helpful to promote the science development. We use the BERT model to vectorize the laureates’ papers and calculate the similarity matrices among them, and detect the research topics of each laureate by Affinity Propagation clustering. We further propose relevant indexes based on Kuhn's ‘essential tension’ hypothesis and divide the laureates’ research topics into the Prize-winning topic, the topic semantically closest to the Prize-winning topic, and other non-Prize-winning topics. The empirical analysis of 117 Nobel laureates in Physics shows that they have a similar research pattern, that is, they tend to explore 2 to 3 topics alternately in different periods, but they usually identify the core research topics early and mainly focus on exploiting them throughout their careers, and other non-Prize-winning topics they explore are often related in some way to the Prize-winning ones.  相似文献   

20.
吴胜  张智光 《图书情报工作》2010,54(10):117-120
参照网站IA和网站开发的一般步骤,提出网站信息分类体系优化方法。该方法可分为分析、评价、设计和实现四个阶段,并将设计阶段分为特征优化、粒度和命名优化、结构优化等环节。各环节优化时,分别可采用自顶向下特征优化方法、粗粒度优先的粒度优化方法、基于统计的命名优化方法、自底向上逐层结构优化方法。最后,应用提出的方法对国家林业局网站现有信息分类体系进行优化。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号