基于AdaBoost的微博垃圾评论识别方法

针对微博上存在的大量垃圾评论,提出一种基于AdaBoost的微博垃圾评论识别方法。该方法首先提取表示微博评论的特征值向量,由8个特征值组成,然后通过AdaBoost算法在这些特征上训练出若干个比随机预测好的弱分类器,最后将得到的弱分类器加权集合成高精度的强分类器。从实际的热门新浪微博中提取评论数据集进行实验,结果表明所选取的8个特征是有效的,该方法对于微博垃圾评论的识别拥有较高的识别率。     

Matching user identities across social networks with limited profile data

Privacy preservation is a primary concern in social networkswhich employ a variety of privacy preservations mechanisms to preserve and protect sensitive user information including age, location, education, interests, and others. The task of matching user identities across different social networks is considered a challenging task. In this work, we propose an algorithm to reveal user identities as a set of linked accounts from different social networks using limited user profile data, i.e., user-name and friendship. Thus, we propose a framework, ExpandUIL, that includes three standalone algorithms based on (i) the percolation graph matching in ExpandFullName algorithm, (ii) a supervised machine learning algorithm that works with the graph embedding, and (iii) a combination of the two, ExpandUserLinkage algorithm. The proposed framework as a set of algorithms is significant as, (i) it is based on the network topology and requires only name feature of the nodes, (ii) it requires a considerably low initial seed, as low as one initial seed suffices, (iii) it is iterative and scalable with applicability to online incoming stream graphs, and (iv) it has an experimental proof of stability over a real ground-truth dataset. Experiments on real datasets, Instagram and VK social networks, show upto 75% recall for linked accounts with 96% accuracy using only one given seed pair.     

Estimating user interaction strength in distributed online networks

User interactions are indispensable for any online network to thrive, especially for BitTorrent‐like and Web real‐time communication‐based distributed online networks that rely on users' collective contributions instead of the help of central servers. User interactions provide fine‐grained information for many applications, such as security enhancement and cooperation promotion. To date, several schemes for estimating user interaction strength in centralized online networks have been proposed. In contrast, we present design, deployment, and analysis of UISE for user interaction strength estimation in distributed online networks. Among the strong points of UISE is that it captures both direct and indirect user interactions, and that it scales with only partial information dissemination. We apply UISE to devise the first distributed scheme for online time estimation and we implement it into Tribler, a distributed online network for media and social applications like file sharing, streaming, and voting. We demonstrate the accuracy and the scalability of UISE with different information dissemination protocols and user behaviors using simulations, emulations, and a real‐world deployment. Copyright © 2015 John Wiley & Sons, Ltd.     

基于自适应差异化图卷积的社交网络新增恶意用户检测

社交网络新增恶意用户检测作为一项分类任务,一直面临着数据样本不足、恶意用户标注稀少的问题。在数据有限的情况下,为了能够精确地检测出恶意用户,提出一种基于自适应差异化图卷积网络的检测方法。该方法通过提取社交网络中的用户特征和社交关系构建社交网络图。构建社交网络图后,计算节点与邻居的相似度,并对邻居进行优先级排序,利用优先级顺序采样关键邻居。关键邻居的特征通过自适应权重的加权平均方式聚合到节点自身,以此更新节点特征。特征更新后的节点通过特征降维和归一化计算得到恶意值,利用恶意值判断用户的恶意性。实验表明该方法和其他方法相比,具有更高的恶意用户查全率和整体查准率,并且能够快速地完成对新增用户的检测,证明了自适应差异化图卷积网络能够有效捕捉到少量样本的关键特征。     

社交网络用户影响力分析ABP算法研究与应用

社交网络作为一种交往方式,已经深入人心。其用户数据在这个大数据时代蕴藏着大量的价值。随着Twitter API的开放,社交网络Twitter俨然成为一个深受欢迎的研究对象,而用户影响力更是其中的研究热点。PageRank算法计算用户影响力已经由来已久,但是它太依赖于用户之间的关注关系,排名不具备时效性。引入用户活跃度的改进PageRank算法,具备一定的时效性,但是不具有足够的说服力和准确性。研究了一种新的基于时间分布用户活跃度的ABP算法,并为不同时段的活跃度加以相应的时效权重因子。最后,以Twitter为研究对象,结合社交关系网,通过实例分析说明ABP算法更具时效性和说服力,可以比较准确地提高活跃用户的排名,降低非活跃用户排名。     

面向微博影响力的社交网络特征分析

社交网络的影响力与其自身的结构特征密切相关。基于新浪微博的数据,对用户的粉丝数、关注数的分布及这些特征之间的关系进行分析,发现用户的粉丝数、关注数、微博数都符合幂律分布;探讨了节点之间的距离特征,发现并证明了微博网络中存在着“小世界”现象;研究了节点之间的链接形成问题,发现链接的形成满足三元闭包原理。以上三方面研究结果,对于探索微博影响力同底层社交网络结构特征的关系、设计微博影响力控制机制具有重要的意义。     

基于忠诚度的社交网络用户发现方法

针对社交网络中提高用户的高黏性问题,提出了一种基于用户忠诚度的用户发现的算法。该算法利用双重RFM模型对用户忠诚度进行计算,挖掘出忠诚度不同分类的用户。首先,通过双重RFM模型动态计算出用户在某一时间段的消费价值与行为价值,得到用户某一时间段的忠诚度;其次,根据用户的忠诚度,确定标度曲线,利用相似度计算找到典型的忠诚用户与不忠诚用户;最后,采用基于模块度的社区发现与独立级联传播模型,发现潜在的忠诚用户与不忠诚用户。在某社交网络的微博数据集上,实现了社会性网络服务（SNS）下用户忠诚度的量化表示,获得了基于用户忠诚度的用户发现结果。实验结果表明,所提算法能够有效挖掘出基于忠诚度的用户分类,可以为社交网站针对用户的个性化推荐及营销等,提供理论支持和实用方法。     

基于SRank的社交网络影响力分析

针对社交网络中用户影响力的评价问题,提出了一种基于SRank的评价算法。基于从社交网络中收集的大规模数据集,结合最近社会学理论研究成果分析PageRank及其改进算法应用于此场景中的不足。在此基础上总结社交网络中信息传播的规律,将用户与社交网络的关系强度定义为用户的人缘值,用来表示用户作为粉丝的信息再传播能力。然后提出了一个通过预测用户信息传播能力大小来分析和度量用户影响力的SRank用户影响力模型。在同样的数据集下相对于PageRank及其改进算法,SRank用户影响力模型获得了更好的影响力预测结果。基于大规模数据的实验结果表明,提出的方法是较为有效的。     

大规模社交网络中高效的关键用户选取方法

针对大规模社交网络及其用户发布消息的历史数据,如何快速有效地选取具有较强信息传播能力的关键用户,提出了一种关键用户选取方法。首先,利用社交网络的结构信息,构建以用户为节点的有向图,利用用户发布消息的历史数据,基于Spark计算框架,定量计算由用户活跃度、转发交互度和信息量占比刻画的权重,从而构建社交网络的有向带权图模型;然后,借鉴PageRank算法,建立用户信息传播能力的度量机制,给出基于Spark的大规模社交网络中用户信息传播能力的计算方法;进而,给出基于Spark的d-距选取算法,通过多次迭代,使得所选取的不同关键用户的信息传播范围尽量少地重叠。建立在新浪微博数据上的实验结果表明,所提方法具有高效性、可行性和可扩展性,对于控制不良突发信息传播、社交网络舆情监控具有一定的支撑作用。     

Developer social networks in software engineering:construction,analysis,and applications

With the increasing popularity of Internet, more and more developers are collaborating together for software development. During the collaboration, a lot of information related to software development, including communication and coordination information of developers, can be recorded in software repositories. The information can be employed to construct Developer Social Networks （DSNs） for facilitating tasks in software engineering. In this paper, we survey recent advances of DSNs and examine three fundamental steps of DSNs, namely construction, analysis, and applications. We summarize the state-of-the-art methods in the three steps and investigate the relationships among them. Furthermore, we discuss the main issues and point out the future opportunities in the study of DSNs.     

社交网络中基于K核分解的意见领袖识别算法

针对在社交网络中挖掘意见领袖时存在的计算复杂度高的难题,提出了一种基于K核分解的意见领袖识别算法CR.首先,基于K核分解方法获取社交网络中的意见领袖候选集,以缩小识别意见领袖的数据规模;然后,提出包括位置相似性和邻居相似性的用户相似性的概念,利用K核值、入度数、平均K核变化率和用户追随者个数计算用户相似性,并根据用户相...     

Web社会网络的粗糙属性图模型及应用

针对Web环境下的社会网络具有信息粗糙性的特征,即Web数据中有大量垃圾内容和垃圾链接,同时很多信息是不完整的、缺失的,且信息有重复现象存在等,在已提出的属性图模型基础上,结合粗糙集理论解决不完备信息的优势,首先提出粗糙顶点属性图和粗糙边属性图,进而给出粗糙属性图的概念,以对Web社会网络结构进行分析,使其能够描述复杂Web社会网络中的不完整信息以及动态变化的链接。其次对粗糙属性图的粗糙特性进行分析,给出粗糙顶点精度、粗糙边精度和粗糙图精度等概念,得出粗糙属性图的精度与顶点和边集属性划分程度有关的结论,即人们对图的认知程度与图的精度密切相关。最后,在中国知网上通过对论文作者进行查询得到粗糙图,并通过不断添加顶点属性,将图顶点划分得越来越精细,挖掘出要查询的作者合作关系图,从而说明粗糙属性图在社会网络分析中符合人们的认知过程。     

基于平均场理论的社会网络中行为扩散的研究

在社会生活中,存在大量的用户之间相互影响相互协调并做出决策的事例,具有广泛的应用。深入研究了基于平均场理论的复杂社会网络中行为扩散模式。设计了特定的扩散模型,该模型考虑了采用某行为的邻居节点绝对数目、相对比率以及节点的总邻居数目对该节点选择行为的影响。采用平均场理论对扩散过程进行分析,研究了网络结构对行为扩散的影响,从理论上得出了如何选择门限值使新行为能够在社会网络中大规模传播成为可能。     

The roles of media capabilities of smartphone-based SNS in developing social capital

Smartphone-based social networking service (SNS) is widely used as a key social platform that promotes users to build and maintain interpersonal relationships. However, little is known about the main characteristics of smartphone-based SNS that strengthen social relationships. By combining studies of mediated-communication namely, media richness and social presence with the social capital theory, this study proposes that the advanced media capabilities of smartphone-based SNS enable users to develop bridging and bonding social capital. Moreover, the study suggests that advanced media richness increases social presence referring to the feeling of being connected with others in virtual environments. As a key outcome of social capital in the context of smartphone-based SNS use, user satisfaction is considered. The results indicate that first, media richness and social presence, which represent media capabilities of smartphone-based SNS, greatly increase bridging and bonding social capital. Second, media richness enhances social presence in the context of smartphone-based SNS use. Finally, bridging and bonding social capital are key determinants of user satisfaction with smartphone-based SNS. Discussion and implications on the results are presented.     

The effects of the self and social identity on the intention to microblog: An extension of the theory of planned behavior

Microblogging has become one of the most popular social communication styles in the world. Much research has already addressed this hot issue; however, studies examining the intentions behind microblogging behaviors are limited. This study extended the theory of planned behavior (TPB) to predict intention to microblog and other behaviors. The results showed that social identity was the greatest predictor of intention, followed by attitude and perceived behavioral control. Social identity fully mediated the effects of subjective norms and self-identity on intention. Intention significantly predicted users' microblogging behaviors. These results have important implications for industry players and marketing managers.     

ML-SOR: Message routing using multi-layer social networks in opportunistic communications

Opportunistic networks are a generalization of DTNs in which disconnections are frequent and encounter patterns between mobile devices are unpredictable. In such scenarios, message routing is a fundamental issue. Social-based routing protocols usually exploit the social information extracted from the history of encounters between mobile devices to find an appropriate message relay. Protocols based on encounter history, however, take time to build up a knowledge database from which to take routing decisions. While contact information changes constantly and it takes time to identify strong social ties, other types of ties remain rather stable and could be exploited to augment available partial contact information. In this paper, we start defining a multi-layer social network model combining the social network detected through encounters with other social networks and investigate the relationship between these social network layers in terms of node centrality, community structure, tie strength and link prediction. The purpose of this analysis is to better understand user behavior in a multi-layered complex network combining online and offline social relationships. Then, we propose a novel opportunistic routing approach ML-SOR (Multi-layer Social Network based Routing) which extracts social network information from such a model to perform routing decisions. To select an effective forwarding node, ML-SOR measures the forwarding capability of a node when compared to an encountered node in terms of node centrality, tie strength and link prediction. Trace driven simulations show that a routing metric combining social information extracted from multiple social network layers allows users to achieve good routing performance with low overhead cost.     

Awareness of cognitive and social behaviour in a CSCL environment

Most distributed and virtual online environments for and pedagogies of computer‐supported collaborative learning (CSCL) neglect the social and social‐emotional aspects underlying the group dynamics of learning and working in a CSCL group. These group dynamics often determine whether the group will develop into a well‐performing team and whether a sound social space emerges. Using a theory‐based CSCL framework, two studies evaluated whether two tools, Radar and Reflector, supported cognitive, social and socio‐emotional aspects of team development, encouraging promotive interaction and group processing in the teams. While not affecting product quality, tool use did lead to groups who perceived their team as being better developed, as having higher levels of group satisfaction and lower levels of conflicts. The results support that promotive interaction and group processing was increased by using Radar and Reflector.     

User requirements of social media for the elderly: a case study in Taiwan

Numerous researchers have proposed website design norms that are suitable for the elderly. However, in the design of community platforms, elderly users were not considered in social media usage. Young and middle-aged people are the main targets in several social media platforms. To co-ordinate the digital lives of elderly users, the emphasis in this study was to determine the problems and to search for solutions. The real requirements and proper solutions for the elderly were integrated by analysing possible factors. This study is an anthropological user centred approach, to explore the verbal behaviour of senior citizens while they accessed Facebook. Facebook, which is a social media platform with a multilingual language interface, is currently used worldwide and served the purpose of an experimental base for this research. By determining the user environments that are suitable for the elderly, including web page accessibility, interface design and real social life transformation, this article proposes the factors for a social media website, the factors for the elderly to use social media platforms, a social media platform design that can be easily used by the elderly and design factors suitable for the elderly.     

Authority updating: An expert authority evaluation algorithm considering post‐evaluation and power indices in social networks

In group assessment, the focus is on finding high‐authority experts to improve the reliability of assessment results. In this study, we propose an authority updating algorithm while considering the power and judgement reliability of an expert on the basis of social networks and post‐evaluations. A network power index is established and used to reflect the power of an expert while considering social networks. The measurement of the judgement reliability of an expert considers the post‐evaluation of the objects selected by experts, thereby more scientifically reflecting the reliability of experts. The analysis shows the following: although the social‐network structure influences the authority of experts, the influence weakens when the assessment group is a highly or even fully connected group; the network effect may increase the authority of some experts and reduce that of others, and it will weaken as the network connectivity increases; moreover, the judgement reliability and authority of an expert while considering post‐evaluation can encourage him/her to make fair assessments and strive to reduce his/her motivation and cognitive biases.     

The social sharing of emotion (SSE) in online social networks: A case study in Live Journal

Social Sharing of Emotion (SSE) occurs when one person shares an emotional experience with another and is considered potentially beneficial. Though social sharing has been shown prevalent in interpersonal communication, research on its occurrence and communication structure in online social networks is lacking. Based on a content analysis of blog posts (n = 540) in a blog social network site (Live Journal), we assess the occurrence of social sharing in blog posts, characterize different types of online SSE, and present a theoretical model of online SSE. A large proportion of initiation expressions were found to conform to full SSE, with negative emotion posts outnumbering bivalent and positive posts. Full emotional SSE posts were found to prevail, compared to partial feelings or situation posts. Furthermore, affective feedback predominated to cognitive and provided emotional support, empathy and admiration. The study found evidence that the process of social sharing occurs in Live Journal, replicating some features of face to face SSE. Instead of a superficial view of online social sharing, our results support a prosocial and beneficial character to online SSE.