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1.
针对在线医疗社区问答文本复杂程度高、结构化程度低的特点,结合卷积神经网络(CNN)和双向长短期记忆神经网络(BiLSTM)两种深度学习模型以及条件随机场(CRF)模型,提出一套适用于在线医疗问答文本的实体识别方法并进行验证.将问答文本进行清洗和BIO标注后,分别用CNN和BiLSTM进行字级别的特征抽取,将通过两种模型抽取到的特征进行融合后放入CRF中训练出实体预测模型,再将问答文本放入训练好的模型中,得到最终的实体识别结果.以关于乳腺癌疾病问答文本为例,研究结果表明,运用该方法得到的识别结果优于其他模型,且识别准确率达到92.3％、召回率达到89.3％、F值达到90.8％. 相似文献
2.
[目的/意义]在非结构化语料集中抽取知识要素,是实现知识图谱的重要环节,本文探索了应用深度学习中的卷积神经网络（CNN）模型进行旅游领域知识关系抽取方法。[方法/过程]抓取专业旅游网站的相关数据建立语料库,对部分语料进行人工标注作为训练集和测试集,通过Python语言编程实现分词、向量化及CNN模型,进行关系抽取实验。[结果/结论]实验结果表明,应用卷积神经网络对非结构化的旅游文本进行关系抽取时能够取得满意的效果（Precision 0.77,Recall 0.76,F1-measure 0.76）。抽取结果通过人工校对进行优化后,可以为旅游知识图谱构建、领域本体构建等工作奠定基础。 相似文献
3.
[目的/意义]研究利用深度学习的循环神经网络GRU结合条件随机场CRF对标注的中文文本序列进行预测,来抽取在线评论文本中的实体-属性。[方法/过程]首先根据设计好的文本序列标注规范,对评论语料分词后进行实体及其属性的命名实体标注,得到单词序列、词性序列和标注序列;然后将单词序列、词性序列转为分布式词向量表示并用于GRU循环神经网络的输入;最后输出层采用条件随机场CRF,输出标签即是实体或属性。[结果/结论]实验结果表明,本文的方法将实体-属性抽取简化为命名实体标注,并利用深度学习的GRU捕获输入数据的上下文语义以及条件随机场CRF获取输出标签的前后关系,比传统的基于规则或一般的机器学习方法具有较大的应用优势。 相似文献
4.
针对现有的评价方面抽取方法无法充分利用评论文本中字词包含的复杂语义问题,提出了一种融合多层次语义的网络评价方面抽取模型.首先将卷积神经网络(CNN)训练的字符表示与Word2Vec预训练的词向量进行拼接,构建字词融合的特征表示,利用注意力机制对字词融合的特征表示进行重要程度标识,获得融合注意力的特征表示;构建由CNN和双向长短期记忆网络(BiLSTM)组成的混合神经网络,利用CNN的强学习能力提取字、词的局部语义特征信息,利用BiLSTM全局特征提取能力捕捉字、词之间长距离的上下文语义信息,实现多层次语义融合,最后利用条件随机场学习标签之间的约束条件,输出评论文本最优的序列标注结果,并以酒店评论文本为实验数据集,对所提模型与方法进行可行性和有效性验证.结果表明:本模型具有更好的评价方面抽取效果,可以为基于文本的评价研究与分析提供优质的数据源. 相似文献
5.
[目的/意义]为了帮助情报学学科背景的就业人员掌握市场对情报学人才的具体需要,为情报学的教育者拟定情报学的教育体系和人才培养的目标提供指导。[方法/过程]采集国内各大招聘网站情报学相关职位招聘公告,构建情报学招聘语料库,基于CRF机器学习模型和Bi-LSTM-CRF、BERT、BERT-Bi-LSTM-CRF深度学习模型,从语料库中抽取5类情报学招聘实体进行挖掘分析。[结果/结论]通过在已有2000篇经过标注的职位招聘公告语料库上开展情报学招聘实体自动抽取对比实验,识别效果最佳的CRF模型的整体F值为85.07%,其中对"专业要求"实体的识别F值达到了91.67%。BERT模型在"专业要求"实体识别任务中更是取得了92.10%的F值。使用CRF模型对全部符合要求的5287篇招聘公告进行实体抽取,构建了情报学招聘实体社会网络,并通过信息计量分析与社会网络分析的方式挖掘隐含知识。 相似文献
6.
【目的/意义】金融领域实体关系抽取是构造金融知识库的基础,对金融领域的文本信息利用具有重要作
用。本文提出金融领域实体关系联合抽取模型,增加了对金融文本复杂重叠关系的识别,可以有效避免传统的流
水线模型中识别错误在不同任务之间的传递。【方法/过程】本文构建了高质量金融文本语料,提出一种新的序列
标注模式和实体关系匹配规则,在预训练语言模型BERT（Bidirectional Encoder Representations from Transformers）
的基础上结合双向门控循环单元 BiGRU（Bidirectional Gated Recurrent Units）与条件随机场 CRF（Conditional
Random Field）构建了端到端的序列标注模型,实现了实体关系的联合抽取。【结果/结论】针对金融领域文本数据
进行实验,实验结果表明本文提出的联合抽取模型在关系抽取以及重叠关系抽取上的F1值分别达到了0.627和
0.543,初步验证了中文语境下本文模型对金融领域实体关系抽取的有效性。【创新/局限】结合金融文本特征提出
了新的序列标注模式并构建了基于BERT的金融领域实体关系联合抽取模型,实现了对金融文本中实体间重叠关
系的识别。 相似文献
7.
[目的/意义]本文针对农业领域提出一种基于融合多重特征词嵌入模型的农业命名实体识别方法，以提高识别准确度。[方法/过程]通过使用结合字符、位置语义、领域知识字典特征等多重特征向量作为嵌入层，充分考虑字符的位置信息和上下文语义信息，并根据农业领域的中文实体的特点改进了单一字符向量嵌入，获得更多的农业实体特征，同时采用双向长短时记忆网络BiLSTM和多头注意力机制来学习文本的长距离依赖信息，再利用条件随机场CRF获得全局最优标注序列。[结果/结论]本文在农业领域中文实体语料数据集中与9种基于基线方法进行对比实验，模型的Precision为92.2%,Recall为92.0%,F1值为92.11%,均优于其他基线模型，说明本文模型对于中文农业命名实体识别更精确。 相似文献
8.
[目的/意义]作为科研人员知识获取、交流与利用的重要场所,虚拟学术社区资源具有数量多、价值高等特征,探索智能问答服务在社区的理论、方法与应用,对推动学术资源高效检索与利用,促进知识服务创新具有重要意义。[方法/过程]梳理虚拟学术社区研究现状与目前知识服务存在的不足,联合双向长短期记忆网络(BiLSTW)、文本相似度等技术作为支撑,基于注意力机制的CNN的智能问答方式构建学术社区内资源的智能问答模型,增加注意力分支以抽取细粒度特征,提高检索速度,提升科研效率。[结果/结论]智能化技术的应用实现学术资源的深度聚合,实现传统信息交互与智能化新技术的协同发展,提升了学术资源利用率,扩大信息资源共建共享。 相似文献
9.
[目的/意义]实体语义关系分类是信息抽取重要任务之一，将非结构化文本转化成结构化知识，是构建领域本体、知识图谱、开发问答系统、信息检索系统的基础工作。[方法/过程]本文详细梳理了实体语义关系分类的发展历程，从技术方法、应用领域两方面回顾和总结了近5年国内外的最新研究成果，并指出了研究的不足及未来的研究方向。[结果/结论]热门的深度学习方法抛弃了传统浅层机器学习方法繁琐的特征工程，自动学习文本特征，实验发现，在神经网络模型中融入词法、句法特征、引入注意力机制能有效提升关系分类性能。 相似文献
10.
[目的/意义]旨在探索虚拟社区用户集体意愿研究。[方法/过程]结合在线问答社区特点,采用结构方程模型,先后利用SPSS 23.0和AMOS 21.0进行数据分析并进行模型验证。[结果/结论]研究认为,虚拟社区感、社会资本均对在线问答社区用户集体意愿产生正向影响;在线互动、线下互动除了直接对在线问答社区用户集体意愿产生正向影响,还可以通过虚拟社区感、社会资本对在线问答社区用户集体意愿产生间接的正向影响。 相似文献
11.
A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
12.
Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
13.
A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
14.
Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
15.
《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
16.
Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
17.
《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
18.
Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
19.
Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment. 相似文献
20.
Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献