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1.
In legal case retrieval, existing work has shown that human-mediated conversational search can improve users’ search experience. In practice, a suitable workflow can provide guidelines for constructing a machine-mediated agent replacing of human agents. Therefore, we conduct a comparison analysis and summarize two challenges when directly applying the conversational agent workflow in web search to legal case retrieval: (1) It is complex for agents to express their understanding of users’ information need. (2) Selecting a candidate case from the SERPs is more difficult for agents, especially at the early stage of the search process. To tackle these challenges, we propose a suitable conversational agent workflow in legal case retrieval, which contains two additional key modules compared with that in web search: Query Generation and Buffer Mechanism. A controlled user experiment with three control groups, using the whole workflow or removing one of these two modules, is conducted. The results demonstrate that the proposed workflow can actually support conversational agents working more efficiently, and help users save search effort, leading to higher search success and satisfaction for legal case retrieval. We further construct a large-scale dataset and provide guidance on the machine-mediated conversational search system for legal case retrieval.  相似文献   

2.
社会选择和社会影响是在线社交网络社群形成的两个主要因素,如果能有效对网络社群中用户和群体进行分类,就可以采取不同的群推荐策略,实现群体满意最大化。利用偏好对表示群用户偏好,利用矩阵分解和贝叶斯个性化排序方法,考查社会选择和影响对用户偏好的影响程度,实现群用户和群体的分类,进而提出2种群推荐策略。最后通过2个数据集的实验验证,表明本文提出的基于用户和群体分类的群推荐策略是有效的。  相似文献   

3.
基于语义网的网络智能导航系统研究   总被引:1,自引:0,他引:1  
高雪霞  田文强 《科技通报》2012,28(2):126-127,133
针对网络智能导航不能根据用户的真实需求,将用户快速、准确地引领到目的地的情况,提出一种基于语义网的网络智能导航系统。通过建立网络信息语义模型和用户需求语义模型,在网络信息和用户之间构建导航语义网,将用户文字描述的具体需求准确理解并输入到导航语义网,在导航语义网中完整理解导航需求,准确实现用户对信息搜索的导航。  相似文献   

4.
Socially similar social media users can be defined as users whose frequently visited locations in their social media histories are similar. Discovering socially similar social media users is important for several applications, such as, community detection, friendship analysis, location recommendation, urban planning, and anomaly user and behavior detection. Discovering socially similar users is challenging due to dataset size and dimensions, spam behaviors of social media users, spatial and temporal aspects of social media datasets, and location sparseness in social media datasets. In the literature, several studies are conducted to discover similar social media users out of social media datasets using spatial and temporal information. However, most of these studies rely on trajectory pattern mining methods or take into account semantic information of social media datasets. Limited number of studies focus on discovering similar users based on their social media location histories. In this study, to discover socially similar users, frequently visited or socially important locations of social media users are taken into account instead of all locations that users visited. A new interest measure, which is based on Levenshtein distance, was proposed to quantify user similarity based on their socially important locations and two algorithms were developed using the proposed method and interest measure. The algorithms were experimentally evaluated on a real-life Twitter dataset. The results show that the proposed algorithms could successfully discover similar social media users based on their socially important locations.  相似文献   

5.
提出了一种同步DS-CDMA无线Ad Hoc网络中的有效用户识别方法,采用跨层设计,将MAC层SEEDEX协议中的调度信息用于物理层的帧编码和用户识别. 接收机首先判断是否存在有效用户,如存在则使用当前时隙所有可能发送数据的节点的扩频码来确定有效用户,不存在则直接丢弃该数据帧,从而减少了接收机的能量消耗. 仿真结果表明,该方法同现存的同类算法比较,减小了运算量,节省了接收机能量,改善了接收机错判概率.  相似文献   

6.
The explosion of online user-generated content (UGC) and the development of big data analysis provide a new opportunity and challenge to understand and respond to public opinions in the G2C e-government context. To better understand semantic searching of public comments on an online platform for citizens’ opinions about urban affairs issues, this paper proposed an approach based on the latent Dirichlet allocation (LDA), a probabilistic topic modeling method, and designed a practical system to provide users—municipal administrators of B-city—with satisfying searching results and the longitudinal changing curves of related topics. The system is developed to respond to actual demand from B-city's local government, and the user evaluation experiment results show that a system based on the LDA method could provide information that is more helpful to relevant staff members. Municipal administrators could better understand citizens’ online comments based on the proposed semantic search approach and could improve their decision-making process by considering public opinions.  相似文献   

7.
Although there is an increasingly number of research about the design and use of conversational agents, it is still difficult for conversational agents to completely replace human service. Therefore, more and more companies have adopted human-AI collaborative systems to deliver customer service. It is important to understand how people obtain information from human-AI collaborative conversations. While the existing work relies on self-reported methods to elicit qualitative feedback from users, we have concluded a categorization system for user messages in human-AI collaborative conversations after a thorough examination of a real-world customer service log, which could objectively reflect the user's information needs. We categorize user messages into five categories and 15 specific types related to three high-level intentions. Two annotators independently classified the same set of 1,478 user messages from 300 conversations and reached a moderate consistency. We summarize and report the characteristics of different message types and compare their usage in sessions with only human, AI, or both representatives. Our results show that different message types vary significantly in usage frequency, length, and text similarities with other messages in a session. Also, the frequency of using different message types in our dataset seems consistent over sessions with different types of representatives. But we also observed some significant differences in a few specific message types across the sessions with different representatives. Our results are used to suggest some areas for improvement and future work in human-AI collaborative conversational systems.  相似文献   

8.
People who are suspected to suffer mental disorders often explore online communities to gather medical information. Such medical information benefits these people by facilitating self-diagnosis and social support for the mental disorders. At the same time, however, misinformation can aggravate mental disorders and worsen psychological status. Focusing on two representative mental illnesses, bipolar and depressive disorders, this study analyzed how users shared their experiences with illness and provided advice. Postings for bipolar and depressive disorders were gathered from subreddit communities and used for semantic network analysis. Results showed that users in both communities described sleep disorder episodes and financial problems with negative emotional expressions. Users in the bipolar disorder community showed more interest in the topic of medication, whereas users in the depressive disorder community were more interested in suicide issues. We discuss how these properties in the subreddit communities can be applied to understand user experiences of bipolar and depressive disorders.  相似文献   

9.
曾子明  李鑫 《情报杂志》2012,31(8):166-170
随着移动互联网的发展,越来越多的用户信息获取过程通过移动终端完成.但当前个性化推荐系统对用户情境的感知能力不足,缺乏为用户提供符合当前情境的个性化信息推荐服务.为此,本文提出了基于贝叶斯方法的情境化用户资源类别偏好学习以及融合该类别偏好的协同过滤个性化信息推荐.运用贝叶斯方法学习用户在不同情境下对各资源类别的偏好,然后将该类别偏好与传统协同过滤推荐算法相结合,生成符合用户当前情境的个性化信息推荐.实验表明本文提出的改进算法可以提高推荐的准确率.  相似文献   

10.
【目的/意义】从海量自助餐用户评论数据中抽取有效关键词构建主题和主题词,协助商家了解用户口碑, 进而更好的改善餐饮行业的管理水平。【方法/过程】通过融合TF-IDF、TextRank和LMKE三种不同的关键词抽取 方法获取最优关键词,再对抽取的关键词进行语义聚类、主题识别、主题词挖掘和主题权重计算,最后在采集的美 团数据集上进行验证方法的有效性。【结果/结论】实验结果表明,三种关键词抽取方法的融合比单个关键词算法效 要好,文本评论聚类后的主题分别是:味道、菜品、环境、服务、价格,主题的重要程度依次是:味道 36.2%、服务 22.9%、价格15.1%、环境13.6%、菜品12.2%。实验结果证实,通过该方法能够有效识别和构建主题及主题词,并计算 出用户对于不同主题关注的重点内容,同时为餐饮行业主题及主题词挖掘和应用研究提供了一定的理论和技术基 础。【创新/局限】提出一种半监督语义聚类的主题识别、主题词构建和主题权重评估方法;不足之处在于本次实验 仅以武汉地区的美食自助餐评论为主,其构建的主题适用性范围有限。  相似文献   

11.
孟秋晴  熊回香 《情报科学》2021,39(6):152-160
【目的/意义】为了向在线医疗社区中的用户自动推荐符合其自身实际需求的医生,本文基于在线问诊文本 信息,提出了基于相似用户与相似医生的混合医生推荐算法。【方法/过程】首先从用户咨询问题出发,找到具有相 似咨询问题的用户,将其所选择的医生作为基于相似用户的推荐集合;然后从医生回答从发,通过LDA主题模型训 练,从医生回答文本集中挖掘出隐含的疾病主题,按主题查找具有相似疾病诊治经验的医生作为推荐集合;最后通 过混合相似度计算融合基于相似用户和相似医生的推荐结果,得到最终推荐列表。【结果/结论】通过对在线医疗社 区“39健康网”进行实证研究,结果表明,利用本文提出的方法进行推荐,能够有效降低数据维度,挖掘文本间的潜 在语义关联,有效缩小语义鸿沟,提升推荐质量,具有较好的推荐效果。【创新/局限】本文仅选取了针对科室的小样 本数据进行实验,且部分参数使用经验值,未来可深入探讨该方法在大规模医疗数据集上的应用。  相似文献   

12.
With the information explosion of news articles, personalized news recommendation has become important for users to quickly find news that they are interested in. Existing methods on news recommendation mainly include collaborative filtering methods which rely on direct user-item interactions and content based methods which characterize the content of user reading history. Although these methods have achieved good performances, they still suffer from data sparse problem, since most of them fail to extensively exploit high-order structure information (similar users tend to read similar news articles) in news recommendation systems. In this paper, we propose to build a heterogeneous graph to explicitly model the interactions among users, news and latent topics. The incorporated topic information would help indicate a user’s interest and alleviate the sparsity of user-item interactions. Then we take advantage of graph neural networks to learn user and news representations that encode high-order structure information by propagating embeddings over the graph. The learned user embeddings with complete historic user clicks capture the users’ long-term interests. We also consider a user’s short-term interest using the recent reading history with an attention based LSTM model. Experimental results on real-world datasets show that our proposed model significantly outperforms state-of-the-art methods on news recommendation.  相似文献   

13.
Recommendation is an effective marketing tool widely used in the e-commerce business, and can be made based on ratings predicted from the rating data of purchased items. To improve the accuracy of rating prediction, user reviews or product images have been used separately as side information to learn the latent features of users (items). In this study, we developed a hybrid approach to analyze both user sentiments from review texts and user preferences from item images to make item recommendations more personalized for users. The hybrid model consists of two parallel modules to perform a procedure named the multiscale semantic and visual analyses (MSVA). The first module is designated to conduct semantic analysis on review documents in various aspects with word-aware and scale-aware attention mechanisms, while the second module is assigned to extract visual features with block-aware and visual-aware attention mechanisms. The MSVA model was trained, validated and tested using Amazon Product Data containing sampled reviews varying from 492,970 to 1 million records across 22 different domains. Three state-of-the-art recommendation models were used as the baselines for performance comparisons. Averagely, MSVA reduced the mean squared error (MSE) of predicted ratings by 6.00%, 3.14% and 3.25% as opposed to the three baselines. It was demonstrated that combining semantic and visual analyses enhanced MSVA's performance across a wide variety of products, and the multiscale scheme used in both the review and visual modules of MSVA made significant contributions to the rating prediction.  相似文献   

14.
李江华  时鹏 《情报杂志》2012,31(4):112-116
Internet已成为全球最丰富的数据源,数据类型繁杂且动态变化,如何从中快速准确地检索出用户所需要的信息是一个亟待解决的问题.传统的搜索引擎基于语法的方式进行搜索,缺乏语义信息,难以准确地表达用户的查询需求和被检索对象的文档语义,致使查准率和查全率较低且搜索范围有限.本文对现有的语义检索方法进行了研究,分析了其中存在的问题,在此基础上提出了一种基于领域的语义搜索引擎模型,结合语义Web技术,使用领域本体元数据模型对用户的查询进行语义化规范,依据领域本体模式抽取文档中的知识并RDF化,准确地表达了用户的查询语义和作为被查询对象的文档语义,可以大大提高检索的准确性和检索效率,详细地给出了模型的体系结构、基本功能和工作原理.  相似文献   

15.
涂军  曹鹏 《情报杂志》2012,31(7):191-194,171
数字图书馆是传统图书馆在信息时代的发展与完善,目前已成为用户获取信息的重要渠道,但由于采用基于关键词的信息检索,缺乏对用户查询语言的深层次理解和分析,难以满足实际的需要.笔者在分析数字图书馆中存在的一系列问题的基础上,融合本体技术构建了基于本体的数字图书馆语义检索模型,并详细阐述了模型中各个模块的主要功能及其实现策略.实验结果表明,该模型取得了很好的预期效果,显著提高了信息检索的效率、准确度和知识获取的深度与广度.  相似文献   

16.
谢海涛  肖倩 《现代情报》2019,39(9):28-40
[目的/意义]对社交媒体中热门新闻的及时识别,有助于加速正面资讯的投送或抑制负面资讯的扩散。当前,基于自然语言处理的传统识别方法正面临社交媒体新生态的挑战:大量新闻内容以图片、音视频形式存在,缺乏用于语义及情感分析的文本。[方法/过程]对此,本文首先将社交网络划分为众多社群,并按其层次结构组织为贝叶斯网络。接着,面向社群构建基于卷积神经网络的热门新闻识别模型,模型综合考虑新闻传播的宏观统计规律及微观传播过程,以提取社群内热门新闻传播的特征。最后,利用贝叶斯推理并结合局部性的模型识别结果进行全局性热度预测。[结果/结论]实验表明,本方法在语义缺失场景下可有效识别热门新闻,其准确度强于基于语义信息的机器学习方法,模型具有良好的时效性、可扩展性和适用性。该研究有助于社交媒体的监管机构及时识别出各类不含语义信息且迅速扩散的热点内容。  相似文献   

17.
如何准确分析用户行为,向用户提供满意的网页信息,一直以来都是个性化信息推荐系统设计的目标。本文在分析现有个性化信息推荐模型的基础上,针对以往研究在推荐兴趣时仅根据语义相关度进行协助性信息推荐,而忽略用户行为规律所包含的潜在兴趣信息的不足,尝试提出一个结合Web语义挖掘和FP-tree规则发现技术的个性化信息推荐模型。该模型利用本体对语义的明确化描述,在挖掘用户行为信息时获取用户兴趣偏好的语义信息,并利用FP-tree技术根据以获取的语义信息推理出用户兴趣行为模式,从而在信息推荐时不仅能准确理解用户兴趣偏好,也能根据用户潜在兴趣规律,推荐给用户更全面的网页信息。  相似文献   

18.
Online video recommender systems help users find videos suitable for their preferences. However, they have difficulty in identifying dynamic user preferences. In this study, we propose a new recommendation procedure using changes of users’ facial expressions captured every moment. Facial expressions portray the users’ actual emotions about videos. We can utilize them to discover dynamic user preferences. Further, because the proposed procedure does not rely on historical rating or purchase records, it properly addresses the new user problem, that is, the difficulty in recommending products to users whose past rating or purchase records are not available. To validate the recommendation procedure, we conducted experiments with footwear commercial videos. Experiment results show that the proposed procedure outperforms benchmark systems including a random recommendation, an average rating approach, and a typical collaborative filtering approach for recommendation to both new and existing users. From the results, we conclude that facial expressions are a viable element in recommendation.  相似文献   

19.
We consider a network of autonomous peers forming a logically global but physically distributed search engine, where every peer has its own local collection generated by independently crawling the Web. A challenging task in such systems is to efficiently route user queries to peers that can deliver high quality results and be able to rank these returned results, thus satisfying the users’ information need. However, the problem inherent with this scenario is selecting a few promising peers out of an a priori unlimited number of peers. In recent research a rather strict notion of semantic overlay networks has been established. In most approaches, peers are connected to other peers based on a rigid semantic profile by clustering them based on their contents. In contrast, our strategy follows the spirit of peer autonomy and creates semantic overlay networks based on the notion of “peer-to-peer dating”. Peers are free to decide which connections they create and which they want to avoid based on various usefulness estimators. The proposed techniques can be easily integrated into existing systems as they require only small additional bandwidth consumption as most messages can be piggybacked onto established communication. We show how we can greatly benefit from these additional semantic relations during query routing in search engines, such as Minerva, and in the JXP algorithm, which computes the PageRank authority measure in a completely decentralized manner.  相似文献   

20.
Recommender Systems are currently highly relevant for helping users deal with the information overload they suffer from the large volume of data on the web, and automatically suggest the most appropriate items that meet users needs. However, in cases in which a user is new to Recommender System, the system cannot recommend items that are relevant to her/him because of lack of previous information about the user and/or the user-item rating history that helps to determine the users preferences. This problem is known as cold-start, which remains open because it does not have a final solution. Social networks have been employed as a good source of information to determine users preferences to mitigate the cold-start problem. This paper presents the results of a Systematic Literature Review on Collaborative Filtering-based Recommender System that uses social network data to mitigate the cold-start problem. This Systematic Literature Review compiled the papers published between 2011–2017, to select the most recent studies in the area. Each selected paper was evaluated and classified according to the depth which social networks used to mitigate the cold-start problem. The final results show that there are several publications that use the information of the social networks within the Recommender System; however, few research papers currently use this data to mitigate the cold-start problem.  相似文献   

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