基于用户属性—关系相似度的好友推荐模型研究

[目的/意义]挖掘潜在好友关系并进行精准的好友推荐服务,已成为社交网络领域研究的热点,基于用户属性-关系相似度的好友推荐模型研究旨在增强用户忠诚度以及在线社区活跃度,提升社区的信息服务准确性和效率。[方法/过程]通过融合用户链接关系与属性特征,提出用户属性-关系相似评价体系;采用因子分析法,计算得出各项目权重以及综合得分;据此构建社交网络相似度矩阵,基于派系划分方法,对用户进行划分分区,最终实现好友推荐服务。[结果/结论]实验结果表明,运用派系划分的基于用户属性-关系推荐模型在推荐列表长度受限情况下的整体表现较优,有效提高推荐精准度。     

基于情景化偏好的移动社交网络信息服务自适应建模研究

构建了移动社交网络基于情景化用户偏好的自适应适配信息服务系统模型,提出了移动社交网络的自适应服务发现方案。解决移动社交网络信息服务的发现与推送的延迟问题,实现高效的移动社交网络信息服务推送,对移动社交网络信息服务资源、知识资源进行科学管理。     

社会化标注系统中个性化信息推荐多维度融合与优化模型研究

[目的/意义]在社会化标注系统自组织运行的基础上，构建个性化信息推荐的多维度融合与优化模型，进而在大数据环境下，为用户提供精准的个性化信息推荐服务，从而进一步丰富个性化信息推荐的理论体系以及拓展个性化信息推荐的研究方法。[方法/过程]首先，对每一种个性化信息推荐方法的优点和不足进行深入分析；然后，将基于图论（社会网络关系）、基于协同过滤以及基于内容（主题）3种个性化信息推荐方法进行多维度深度融合，构建个性化信息推荐多维度融合模型；最后，对社会化标注系统中个性化信息推荐多维度融合模型进行优化，从而解决个性化推荐过程中用户"冷启动"、数据稀疏性和用户偏好漂移等问题。[结果/结论]通过综合考虑现有的基于图论（社会网络关系）、基于协同过滤以及基于内容（主题）的个性化信息推荐方法各自的贡献和不足，实现3种方法之间的多维度深度融合，并结合心理认知、用户情境以及时间、空间等优化因素，最终构建出社会化标注系统中个性化信息推荐多维度融合与优化模型。     

基于用户相似度与信任度的虚拟学术社区中学者推荐研究

【目的/意义】研究从用户节点和网络全局两个视角出发,基于用户相似度与信任度对虚拟学术社区中学者进行推荐,提高学者推荐的质量。【方法/过程】首先,利用LDA主题模型挖掘学者发表的博文主题,计算博文相似度;通过学者共同好友比例计算好友相似度;然后将博文相似度和好友相似度融合计算用户相似度;最后,融合用户相似度和信任度进行学者推荐。【结果/结论】提出虚拟学术社区中基于用户相似度与信任度的学者推荐方法,综合利用用户节点和网络全局信息,为虚拟学术社区用户进行学者推荐。【创新/局限】从用户节点和网络全局两个角度进行学者信息融合,有效提高了虚拟学术社区中学者推荐的质量。局限在于本文主要考虑的是学者在网络全局中的信任度,用户节点间的交互信任关系还有待进一步研究。     

基于改进SVM的新疆北部地区积雪面积反演研究——以天山山区中段为例

积雪面积是融雪径流模型中变量数据输入之一,准确的获取雪盖范围是进行流域尺度融雪水文过程研究的关键,在水资源管理及洪水预报中具有重要意义.本文以天山山区中段为例,利用MODIS数据,提出了结合混合光谱分解的积雪分量及灰度共生矩阵提取的纹理特征的SVM分类方法,对研究区积雪面积信息提取进行了研究.结果表明:通过利用混合光谱分解的积雪分量作为SVM的特征输入,总体分类精度比传统SVM分类结果有了一些提高.同时考虑结合基于灰度共生矩阵提取的纹理特征用于分类中,总体精度比传统SVM方法提高了1.081％,制图精度达到了99.01％.本文提出的分类方法能够适应特征组合之间的非线性关系,从而能提供更多的区域地物空间分布信息,能够调整无样本地表类型地区的积雪面积反演,对今后的融雪水文过程研究有重要意义.     

一种面向高校图书馆的个性化图书推荐系统

个性化图书推荐主要是以用户特征和借阅行为为挖掘对象,通过获取用户的兴趣特征及隐含的需求模式,实现用户与图书相互关联的个性化图书推荐服务。本文通过挖掘用户的背景信息构建用户特征模型,然后在设计喜好值计算、用户相似度计算和内容相似度计算以及标签信息获取方法的基础上,研究多种不同的图书推荐方法,以挖掘用户的潜在信息需求。最后利用图书馆的真实数据设计面向高校图书馆的个性化图书推荐系统,同时以标准网络数据集通过实验验证来评估推荐方法的有效性。     

Group event recommendation based on graph multi-head attention network combining explicit and implicit information

In event-based social networks (EBSN), group event recommendation has become an important task for groups to quickly find events that they are interested in. Existing methods on group event recommendation either consider just one type of information, explicit or implicit, or separately model the explicit and implicit information. However, these methods often generate a problem of data sparsity or of model vector redundancy. In this paper, we present a Graph Multi-head Attention Network (GMAN) model for group event recommendation that integrates the explicit and implicit information in EBSN. Specifically, we first construct a user-explicit graph based on the user's explicit information, such as gender, age, occupation and the interactions between users and events. Then we build a user-implicit graph based on the user's implicit information, such as friend relationships. The incorporated both explicit and implicit information can effectively describe the user's interests and alleviate the data sparsity problem. Considering that there may be a correlation between the user's explicit and implicit information in EBSN, we take the user's explicit vector representation as the input of the implicit information aggregation when modeling with graph neural networks. This unified user modeling can solve the aforementioned problem of user model vector redundancy and is also suitable for event modeling. Furthermore, we utilize a multi-head attention network to learn richer implicit information vectors of users and events from multiple perspectives. Finally, in order to get a higher level of group vector representation, we use a vanilla attention mechanism to fuse different user vectors in the group. Through experimenting on two real-world Meetup datasets, we demonstrate that GMAN model consistently outperforms state-of-the-art methods on group event recommendation.     

基于大规模数据分析的融合面部特征的信用风险预测模型

【目的/意义】个人违约信用风险是网络借贷平台所面临的主要风险之一,引起了金融机构的广泛重视。传 统的P2P网络借贷违约风险预测模型通常使用历史数据建模,而模型的对象主要为历史履约和违约因素,由此带来 的因素选择偏差问题会影响模型的泛化能力和风险预测能力。【方法/过程】本文引入面部特征大数据分析方法,利 用深度学习技术自动抽取人脸面部特征变量,将其作为一个新的维度融入以历史借贷数据为核心的信用风险评价 系统,建构新型信用风险预测模型。【结果/结论】论文基于南京某互联网金融公司提供的数据集进行实验与实证分 析,结果表明本文提出的模型优于传统的违约风险预测模型。【创新/局限】本研究的创新点为一方面基于大数据分 析方法挖掘了真实借款人面部特征在预测互联网信贷背景下的贷款违约中的作用,为互联网信贷的信用风险预测 模型提供了新的数据维度,另一方面为使用深度学习方法自动识别和提取大规模图片数据集中的面部特征提供了 新的思路。     

Candidate sentence selection for extractive text summarization

Text summarization is a process of generating a brief version of documents by preserving the fundamental information of documents as much as possible. Although most of the text summarization research has been focused on supervised learning solutions, there are a few datasets indeed generated for summarization tasks, and most of the existing summarization datasets do not have human-generated goal summaries which are vital for both summary generation and evaluation. Therefore, a new dataset was presented for abstractive and extractive summarization tasks in this study. This dataset contains academic publications, the abstracts written by the authors, and extracts in two sizes, which were generated by human readers in this research. Then, the resulting extracts were evaluated to ensure the validity of the human extract production process. Moreover, the extractive summarization problem was reinvestigated on the proposed summarization dataset. Here the main point taken into account was to analyze the feature vector to generate more informative summaries. To that end, a comprehensive syntactic feature space was generated for the proposed dataset, and the impact of these features on the informativeness of the resulting summary was investigated. Besides, the summarization capability of semantic features was experienced by using GloVe and word2vec embeddings. Finally, the use of ensembled feature space, which corresponds to the joint use of syntactic and semantic features, was proposed on a long short-term memory-based neural network model. ROUGE metrics evaluated the model summaries, and the results of these evaluations showed that the use of the proposed ensemble feature space remarkably improved the single-use of syntactic or semantic features. Additionally, the resulting summaries of the proposed approach on ensembled features prominently outperformed or provided comparable performance than summaries obtained by state-of-the-art models for extractive summarization.     

基于隐性社会网络社团划分的推荐方法研究

结合社会网络分析的推荐方法研究已成为热点。电子商务中用户的动态行为异常丰富,隐含了用户的关联关系,利用这些信息进行商品推荐是个新研究思路。分析电子商务系统中用户动态行为关联关系及用户间明确好友关系形成复杂隐性社会网络,将社团划分算法应用到该网络中,则社团内部用户联系紧密且具有更相似的消费偏好,据此设计了电子商务中社团内部的推荐方法,应用R语言进行了算法的验证并与传统的协同过滤算法进行比较。实验表明,该推荐算法提高了推荐的质量,缓解了传统推荐算法中数据稀疏性及冷启动问题等。     

Meta-learning adaptation network for few-shot link prediction in heterogeneous social networks

Link prediction, which aims to predict future or missing links among nodes, is a crucial research problem in social network analysis. A unique few-shot challenge is link prediction on newly emerged link types without sufficient verification information in heterogeneous social networks, such as commodity recommendation on new categories. Most of current approaches for link prediction rely heavily on sufficient verified link samples, and almost ignore the shared knowledge between different link types. Hence, they tend to suffer from data scarcity in heterogeneous social networks and fail to handle newly emerged link types where has no sufficient verified link samples. To overcome this challenge, we propose a model based on meta-learning, called the meta-learning adaptation network (MLAN), which acquires transferable knowledge from historical link types to improve the prediction performance on newly emerged link types. MLAN consists of three main components: a subtask slicer, a meta migrator, and an adaptive predictor. The subtask slicer is responsible for generating community subtasks for the link prediction on historical link types. Subsequently, the meta migrator simultaneously completes multiple community subtasks from different link types to acquire transferable subtask-shared knowledge. Finally, the adaptive predictor employs the parameters of the meta migrator to fuse the subtask-shared knowledge from different community subtasks and learn the task-specific knowledge of newly emerged link types. Experimental results conducted on real-world social media datasets prove that our proposed MLAN outperforms state-of-the-art models in few-shot link prediction in heterogeneous social networks.     

面向语义缺失场景的社交媒体中热门新闻识别方法研究

[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。     

A big data analytics framework for detecting user-level depression from social networks

Depression is one of the most common mental health problems worldwide. The diagnosis of depression is usually done by clinicians based on mental status questionnaires and patient's self-reporting. Not only do these methods highly depend on the current mood of the patient, but also people who experience mental illness are often reluctantly seeking help. Social networks have become a popular platform for people to express their feelings and thoughts with friends and family. With the substantial amount of data in social networks, there is an opportunity to try designing novel frameworks to identify those at risk of depression. Moreover, such frameworks can provide clinicians and hospitals with deeper insights about depressive behavioral patterns, thereby improving diagnostic process. In this paper, we propose a big data analytics framework to detect depression for users of social networks. In addition to syntactic and syntax features, it focuses on pragmatic features toward modeling the intention of users. User intention represents the true motivation behind social network behaviors. Moreover, since the behaviors of user's friends in the network are believed to have an influence on the user, the framework also models the influence of friends on the user's mental states. We evaluate the performance of the proposed framework on a massive real dataset obtained from Facebook and show that the framework outperforms existing methods for diagnosing user-level depression in social networks.     

A novel recommendation method based on social network using matrix factorization technique

The rapid development of information technology and the fast growth of Internet have facilitated an explosion of information which has accentuated the information overload problem. Recommender systems have emerged in response to this problem and helped users to find their interesting contents. With increasingly complicated social context, how to fulfill personalized needs better has become a new trend in personalized recommendation service studies. In order to alleviate the sparsity problem of recommender systems meanwhile increase their accuracy and diversity in complex contexts, we propose a novel recommendation method based on social network using matrix factorization technique. In this method, we cluster users and consider a variety of complex factors. The simulation results on two benchmark data sets and a real data set show that our method achieves superior performance to existing methods.     

A deep recommendation model of cross-grained sentiments of user reviews and ratings

The matrix factorization model based on user-item rating data has been widely studied and applied in recommender systems. However, data sparsity, the cold-start problem, and poor explainability have restricted its performance. Textual reviews usually contain rich information about items’ features and users’ sentiments and preferences, which can solve the problem of insufficient information from only user ratings. However, most recommendation algorithms that take sentiment analysis of review texts into account are either fine- or coarse-grained, but not both, leading to uncertain accuracy and comprehensiveness regarding user preference. This study proposes a deep learning recommendation model (i.e., DeepCGSR) that integrates textual review sentiments and the rating matrix. DeepCGSR uses the review sets of users and items as a corpus to perform cross-grained sentiment analysis by combining fine- and coarse-grained levels to extract sentiment feature vectors for users and items. Deep learning technology is used to map between the extracted feature vector and latent factor through the rating-based matrix factorization model and obtain deep, nonlinear features to predict the user's rating of an item. Iterative experiments on e-commerce datasets from Amazon show that DeepCGSR consistently outperforms the recommendation models LFM, SVD++, DeepCoNN, TOPICMF, and NARRE. Overall, comparing with other recommendation models, the DeepCGSR model demonstrated improved evaluation results by 14.113% over LFM, 13.786% over SVD++, 9.920% over TOPICMF, 5.122% over DeepCoNN, and 2.765% over NARRE. Meanwhile, the DeepCGSR has great potential in fixing the overfitting and cold-start problems. Built upon previous studies and findings, the DeepCGSR is the state of the art, moving the design and development of the recommendation algorithms forward with improved recommendation accuracy.     

A Cross-Media Deep Relationship Classification Method Using Discrimination Information

Relation classification is one of the most fundamental tasks in the area of cross-media, which is essential for many practical applications such as information extraction, question&answer system, and knowledge base construction. In the cross-media semantic retrieval task, in order to meet the needs of cross-media uniform representation and semantic analysis, it is necessary to analyze the semantic potential relationship and construct semantic-related cross-media knowledge graph. The relationship classification technology is an important part of solving semantic correlation classification. Most of existing methods regard relation classification as a multi-classification task, without considering the correlation between different relationships. However, two relationships in the opposite directions are usually not independent of each other. Hence, this kind of relationships are easily confused in the traditional way. In order to solve the problem of confusing the relationships of the same semantic with different entity directions, this paper proposes a neural network fusing discrimination information for relation classification. In the proposed model, discrimination information is used to distinguish the relationship of the same semantic with different entity directions, the direction of entity in space is transformed into the direction of vector in mathematics by the method of entity vector subtraction, and the result of entity vector subtraction is used as discrimination information. The model consists of three modules: sentence representation module, relation discrimination module and discrimination fusion module. Moreover, two fusion methods are used for feature fusion. One is a Cascade-based feature fusion method, and another is a feature fusion method based on convolution neural network. In addition, this paper uses the new function added by cross-entropy function and deformed Max-Margin function as the loss function of the model. The experimental results show that the proposed discriminant feature is effective in distinguishing confusing relationships, and the proposed loss function can improve the performance of the model to a certain extent. Finally, the proposed model achieves 84.8% of the F1 value without any additional features or NLP analysis tools. Hence, the proposed method has a promising prospect of being incorporated in various cross-media systems.     

基于内部网络结构的知识推荐系统设计研究

研究了组织内部网络结构对知识共享和知识推荐的影响。首先在相关理论分析的基础上,选取某科研团队,设计调查问卷收集网络关系资料,通过SNA描绘出该团队的正式网络以及合并了非正式网络关系的复杂网络,并使用社会网络的相关测量指标对比分析,设计知识共享推荐系统,最后证明融合了正式网络关系和非正式网络关系的复杂网络更能有效地促进知识的流通和共享。     

An impact of time and item influencer in collaborative filtering recommendations using graph-based model

Recommender Systems deal with the issue of overloading information by retrieving the most relevant sources in the wide range of web services. They help users by predicting their interests in many domains like e-government, social networks, e-commerce and entertainment. Collaborative Filtering (CF) is the most promising technique used in recommender systems to give suggestions based on liked-mind users’ preferences. Despite the widespread use of CF in providing personalized recommendation, this technique has problems including cold start, data sparsity and gray sheep. Eventually, these problems lead to the deterioration of the efficiency of CF. Most existing recommendation methods have been proposed to overcome the problems of CF. However, they fail to suggest the top-n recommendations based on the sequencing of the users’ priorities. In this research, to overcome the shortcomings of CF and current recommendation methods in ranking preference dataset, we have used a new graph-based structure to model the users’ priorities and capture the association between users and items. Users’ profiles are created based on their past and current interest. This is done because their interest can change with time. Our proposed algorithm keeps the preferred items of active user at the beginning of the recommendation list. This means these items come under top-n recommendations, which results in satisfaction among users. The experimental results demonstrate that our algorithm archives the significant improvement in comparison with CF and other proposed recommendation methods in terms of recall, precision, f-measure and MAP metrics using two benchmark datasets including MovieLens and Superstore.     

基于多模态特征融合的社交媒体虚假新闻检测

【目的/意义】社交媒体在改变新闻传播以及人类获取信息方式的同时,也成为了虚假新闻传播的主要渠 道。因此,快速识别社交媒体中的虚假新闻,扼制虚假信息的传播,对净化网络空间、维护公共安全至关重要。【方 法/过程】为了有效识别社交媒体上发布的虚假新闻,本文基于对虚假新闻内容特征的深入剖析,分别设计了文本 词向量、文本情感、图像底层、图像语义特征的表示方法,用以提取社交网络中虚假新闻的图像特征信息和文本特 征信息,构建多模态特征融合的虚假新闻检测模型,并使用MediaEval2015数据集对模型性能进行效果验证。【结果/ 结论】通过对比分析不同特征组合方式和不同分类方法的实验结果,发现融合文本特征和图像特征的多模态模型 可以有效提升虚假新闻检测效果。【创新/局限】研究从多模态的角度设计了虚假新闻检测模型,融合了文本与图像 的多种特征。然而采用向量拼接来实现特征融合,不仅无法实现各种特征的充分互补,而且容易造成维度灾难。