一种基于词序的社会情感演变分析模型

提出了一种基于词序的社会情感演变分析模型(BTMESE),模型通过引入文档中词与词之间的前后关联性,以期有效地揭示时间、文本、情感三种信息之间的潜在联系,进而追踪社会情感演变趋势,进一步提高情感分析的准确率。该模型可应用于情感预测、时间预测等领域。通过在真实世界的数据集上进行验证,结果证明该模型简单有效,能够较好地进行社会情感分析。     

在线社会网络的k-shell结构研究

分析研究了Twitter与You Tube两个在线社会网络的结构。用k-shell(k-壳)分解法对网络分解,并对比分析了它们的入(出)度、入(出)k-shell、以及度与k-shell之间的关系,发现它们之间有较大的差异。You Tube的入(出)度、入(出)k-shell分布均服从幂律分布,而Twitter的分布服从漂移幂律分布、指数截断的幂律分布,但它们的度与k-shell关系基本相同,都未表现出较强的相关性。此外,根据度相关系数的定义还提出k-shell相关性的定义及其计算方法,并用来刻画网络k-shell之间的同(异)配性。     

基于社会网络的群体情绪模型

为了能够深入认识群体事件中群体情绪的演化过程,提出了基于社会人际关系的群体情绪模型构建方法。以小世界网络模型构建个体间社会关系,并通过引入情感关系参数表达现实生活中个体间的强情感、弱情感和陌生关系。基于Bosse等人提出的群体情绪模型,以社会网络作为情绪传播媒介对不同类别人际关系情境中群体情绪的演化态势进行了实验模拟,分析了近邻数K、重连概率P和情感关系R对群体情绪涌现所产生的影响。结果表明,情感关系越亲近、近邻数K越大,群体情绪最终的强度则越强烈,情绪涌现所需时间越短;重连概率P对群体情绪强度也有微弱影响,但作用并不十分显见。     

在线社会网络的网络结构和信息传播研究综述

随着在线社会网络的大规模应用和普及, 亟需对在线社会网络进行深入研究分析。在线社会网络的网络结构和信息传播研究是该领域中的两大研究热点和关键问题。网络结构包括关键节点、网络关系以及社团的挖掘, 通过对网络结构的分析可以掌握被分析网络中存在的社团、节点之间的关系以及关键节点等, 而这种分析对于国家及时掌握在线社会网络的舆情、公司广告在网络上投放策略的制定都具有极大的帮助。对在线社会网络信息传播的研究主要有信息传播动力模型、信息传播源和路径的发现与描绘、信息传播的最大化和最小化等, 通过对在线社会网络信息传播的研究, 人们可以对在线社会网络信息传播的影响进行预测和干预, 从而可以将信息传播的影响按照有利的方向引导。综述了在线社会网络的网络结构和信息传播的研究现状, 并对这两方面的主要研究方法及技术的优势和不足以及适用场合进行了对比分析。     

在线社交网络中的位置服务研究进展与趋势

在基于位置的社交网络中, 用户通过发布嵌入了位置数据的媒体信息获得服务, 如位置或好友推荐、旅行路线推荐等。用户和位置都是网络的主体, 位置作为桥梁将用户的虚拟网络世界与现实世界联系起来。综述了基于位置的在线社交网络中的位置信息获取、用户识别、位置识别、信息的共享与传播及位置隐私的相关研究, 预测了基于位置的在线社交网络未来的研究趋势。     

成本控制下的快速影响最大化算法

针对成本控制下影响最大化时间复杂度高的问题,提出一种快速的最大化算法BCIM。首先提出对初始节点进行多次传播的传播模型;其次选择高影响力节点作为备用种子,并基于近距离影响减少计算节点影响范围的工作量;最后利用动态规划方法在每组备用种子中最多选择一个种子。仿真实验表明,与随机算法Random、每轮取影响力增量最大的节点的贪心算法Greedy_MII、每轮取影响力增量与成本比值最大的节点的贪心算法Greedy_MICR相比,在影响范围上,BICM接近或优于Greedy_MICR及Greedy_MII,远次于Random;在种子集合的质量上,BCIM、Greedy_MICR、Greedy_MII三者差距较小,但都远远好于Random;在运行时间上,BCIM是Random的几倍,而两个贪心算法都是BCIM的几百倍。BCIM算法能在较短时间内找到更有效的种子集合。     

社交网络影响的不良信息扩散建模及最优控制策略

针对已有不良信息传播模型没有考虑不同社交网络间信息扩散情况,利用图论中的连通性原理,建立了多个社交网络间不良信息扩散的动力学模型,并且将优化控制理论应用到模型中。通过最优控制原理,证明了最优控制策略的存在性,进一步得到了不良信息扩散的优化控制模型。实验结果表明,引入优化控制措施可以有效抑制不良信息扩散规模,而且控制策略的强度可以根据需要进行动态调整。另外,通过模拟不同社交网络间是否有信息相互传递,发现社交网络间的信息传递会增大不良信息扩散的规模和速度。     

SSDBA: the stretch shrink distance based algorithm for link prediction in social networks

In the field of social network analysis,Link Predic-tion is one of the hottest topics which has been attracted attentions in academia and industry.So far,literatures for solving link prediction can be roughly divided into two categories:similarity-based and learning-based methods.The learning-based methods have higher accuracy,but their time complexities are too high for complex networks.However,the similarity-based methods have the advantage of low time consumption,so improving their accuracy becomes a key issue.In this paper,we employ community structures of social networks to improve the prediction accuracy and propose the stretch shrink distance based algorithm(SSDBA),In SSDBA,we first detect communities of a social network and identify active nodes based on community average threshold(CAT)and node average threshold(NAT)in each community.Second,we propose the stretch shrink distance(SSD)model to iteratively calculate the changes of distances between active nodes and their local neighbors.Finally,we make predictions when these links'distances tend to converge.Furthermore,extensive parameters learning have been carried out in experiments.We compare our SSDBA with other popular approaches.Experimental results validate the effectiveness and efficiency of proposed algorithm.     

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.     

在线社会网络演化模型

在分析在线社会网络的拓扑结构、特征及演化规律的基础上,借鉴了前人网络模型的思想,提出了在线社会网络演化模型,引入动态的加权方式,提出了一种在线社会网络演化模型。理论分析和仿真表明：在线社会网络演化模型具有无标度和小世界特性,点权、边权、度分布呈现幂律特性,具有较多的簇系数、较小的路径长度且可调。这种无标度和小世界特性与现实中的在线社会网络较为一致。     

社会网络的动态建模与变化检测技术

动态网络分析是社会网络数据挖掘的重要手段。基于此,归纳社会网络动态行为,介绍针对不同网络变化原因的对应分析方法,从动态建模分析和网络变化检测两方面综述动态社会网络分析技术,并总结各种方法的适用范围及优缺点,提出该领域需要进一步研究的问题,探讨动态社会网络分析的发展方向。     

A survey on privacy in decentralized online social networks

Decentralized Online Social Networks (DOSNs) have recently captured the interest of users because of the more control given to them over their shared contents. Indeed, most of the user privacy issues related to the centralized Online Social Network (OSN) services (such as Facebook or Google+) do not apply in the case of DOSNs because of the absence of the centralized service provider. However, these new architectures have motivated researchers to investigate new privacy solutions that allow DOSN’s users to protect their contents by taking into account the decentralized nature of the DOSNs platform.In this survey, we provide a comprehensive overview of the privacy solutions adopted by currently available DOSNs, and we compare them by exploiting several criteria. After presenting the differences that existing DOSNs present in terms of provided services and architecture, we identify, for each of them, the privacy model used to define the privacy policies and the mechanisms for their management (i.e., initialization and modification of the privacy policy). In addition, we evaluate the overhead introduced by the security mechanisms adopted for privacy policy management and enforcement by discussing their advantages and drawbacks.     

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.     

Asymptotic behaviours of a class of threshold models for collective action in social networks

A class of dynamic threshold models is proposed for describing the upset of collective actions in social networks. The agents of the network have to decide whether to undertake certain action or not. They make their decision by comparing the activity level of their neighbours with a time-varying threshold, evolving according to a time-invariant opinion dynamic model. Key features of the model are a parameter representing the degree of self-confidence of the agents and the mechanism adopted by the agents to evaluate the activity level of their neighbours. The case in which a radical agent, initially eager to undertake the action, interacts with a group of ordinary agents, is considered. The main contribution of the paper is the complete characterisation of the asymptotic behaviours of the network, for three different graph topologies. The asymptotic activity patterns are determined as a function of the self-confidence parameter and of the initial threshold of the ordinary agents. Numerical validation on a real ego network shows that the theoretical results obtained for simple graph structures provide useful insights on the network behaviour in more complex settings.     

社会网络中的影响力最大化问题

影响力最大化问题要求在网络中选取若干节点,使得以它们为初始节点进行信息传播时,在网络中产生的影响能够达到最大。影响力最大化问题是近十年来社会网络中的研究热点之一,其研究不仅具有理论意义,并且还具有应用前景。介绍了影响力最大化问题产生的背景,分析了问题的研究现状、研究用的几种主要传播模型以及解决问题的几种主要算法。最后,讨论了该研究面临的一些问题,对未来可能发展的研究方向进行了展望。     

社交网络中对立影响最大化算法

已有社交网络影响力传播的研究工作主要关注单源信息传播情形,较少考虑对立的传播形式。针对对立影响最大化问题,扩展热量传播模型为多源热量传播模型,并提出一种预选式贪心近似（PSGA）算法。为验证算法有效性,选取7种具有代表性的种子挖掘方法,以对立影响最大化传播收益、算法运行时间及种子的富集程度为评价指标,在不同种类社会网络数据集上开展实验。结果表明,PSGA算法所选的种子传播能力更强,且密集程度低、表现稳定,在传播初期占据优势,可以认为PSGA算法能够解决对立影响最大化问题。     

Examining online citizenship behaviours in social network sites: a social capital perspective

As users have flocked to social network sites (SNSs), these sites have gained tremendous scale and concomitant social influence. This growth has come at the cost of social disruption caused by the posting of abusive comments and rumours that turn out to be false. To combat these negative phenomena, this study proposes SNS citizenship behaviour and examines it from the perspective of social capital theory. This study further examines how the key characteristics of SNS in terms of the concept of customer value affect social capital development in an SNS context. The test results explain that the structural, relational, and cognitive dimensions of social capital have significant direct and indirect effects on the SNS citizenship behaviour. These findings also explain that four key characteristics (exploration, communication support, playfulness, and responsiveness) of SNS affect the three dimensions of social capital. This study contributes to the literature in its establishment of the concept of SNS citizenship behaviour and examines it from the social capital theory perspective. Its findings have practical implications through its guidance on how to develop SNS features and manage these sites for the citizenship behaviour of their users, which are achievements for the harmonious and effective functioning of SNS.     

Analyzing market performance via social media: a case study of a banking industry crisis

Analyzing market performance via social media has attracted a great deal of attention in the finance and machine-learning disciplines.However,the vast majority of research does not consider the enormous influence a crisis has on social media that further affects the relationship between social media and the stock market.This article aims to address these challenges by proposing a multistage dynamic analysis framework.In this framework,we use an authorship analysis technique and topic model method to identify stakeholder groups and topics related to a special firm.We analyze the activities of stakeholder groups and topics in different periods of a crisis to evaluate the crisis’s influence on various social media parameters.Then,we construct a stock regression model in each stage of crisis to analyze the relationships of changes among stakeholder groups/topics and stock behavior during a crisis.Finally,we discuss some interesting and significant results,which show that a crisis affects social media discussion topics and that different stakeholder groups/topics have distinct effects on stock market predictions during each stage of a crisis.     

基于k-核过滤的社交网络影响最大化算法

针对现有社交网络影响最大化算法影响范围小和时间复杂度高的问题,提出一种基于独立级联模型的k-核过滤算法。首先,介绍了一种节点影响力排名不依赖于整个网络的现有影响力最大化算法;然后,通过预训练k,找到对现有算法具有最佳优化效果且与选择种子数无关的k值;最后,通过计算图的k-核过滤不属于k-核子图的节点和边,在k-核子图上执行现有影响最大化算法,达到降低计算复杂度的目的。为验证k-核过滤算法对不同算法有不同的优化效果,在不同规模数据集上进行了实验。结果显示,应用k-核过滤算法后：与原PMIA算法相比,影响范围最多扩大13.89%,执行时间最多缩短8.34%;与原核覆盖算法（CCA）相比,影响范围没有太大差异,但执行时间最多缩短28.5%;与OutDegree算法相比,影响范围最多扩大21.81%,执行时间最多缩短26.96%;与Random算法相比,影响范围最多扩大71.99%,执行时间最多缩短24.21%。进一步提出了一种新的影响最大化算法GIMS,它比PMIA和IRIE的影响范围更大,执行时间保持在秒级别,而且GIMS算法的k-核过滤算法与原GIMS算法的影响范围和执行时间差异不大。实验结果表明,k-核过滤算法能够增大现有算法选择种子节点集合的影响范围,并且减少执行时间;GIMS算法具有更好的影响范围效果和执行效率,并且更加鲁棒。     

The deep structure of organizational online networking – an actor‐oriented case study

While research on organizational online networking recently increased significantly, most studies adopt quantitative research designs with a focus on the consequences of social network configurations. Very limited attention is paid to comprehensive theoretical conceptions of the complex phenomenon of organizational online networking. We address this gap by adopting a theoretical framework of the deep structure of organizational online networking with a focus on their emerging meaning for the employees. We apply and assess the framework in a qualitative case study of a large‐scale implementation of a corporate social network site (SNS) in a global organization. We reveal organizational online networking as a multi‐dimensional phenomenon with multiplex relationships that are unbalanced, primarily consist of weak ties and are subject to temporal change. Further, we identify discourse drivers and information retrievers as two mutually interdependent actor roles as an explanation for uneven levels of user contributions to the SNS. Based on our analysis, we elicit abstract order principles, such as topical discourses, and identify transactive memory theory as a potent explanation of the evolving interaction structures. We finally discuss how the deep structure framework can contribute to future research on organizational networks.