重构强弱关系：在线社交网络中的三维关系模型及应用

关系的概念是社会网络分析的核心,关系强度的测量建立在强弱关系理论基础之上,随着在线社交网络的发展,关系的细分更加必要,三维关系模型旨在改进静态、二元的强弱关系模式,从三个维度对关系强度进行重新构造,即心理维度、结构维度及工具维度。应用文献分析和实证分析的方法,建立了在线网络中的关系测量模型,结果表明,通过量化在线网络中用户的互动行为,可以将每个维度的关系强度归一化为 [0,1] 的连续变量,同现有方法相比,三维关系可以细分关系图谱,在设计SNS功能、隐私控制、朋友推荐及信息扩散等方面,三维关系模型无疑具有重要的理论指导作用。     

基于专利合作网络的北京国际科技合作分析

以美国专利商标局申请库收录的2001-2013年北京国际科技合作专利为数据源,运用文献计量和社会网络的方法对北京国际科技合作专利的逐年发展情况,主要合作国家、重点科研机构、活跃人才以及热点领域的合作情况作出全面的分析和系统的解读,揭示了北京国际科技合作专利快速增长等现状特征,探讨了当前北京国际科技合作在知识产权共享、企业创新能力等方面的问题,从政府的支持力度和要素流动等角度提出了建议对策。     

基于均衡理论的服务覆盖网络路由算法研究

基于Wardrop均衡理论提出了一种跨域的自适应的多下一跳路由算法,仿真实验表明该算法在满足用户QoS需求的同时,能在SON经营者和ISP提供商双方利益博弈的过程中找到均衡点,既均衡网络负载提高网络利用率,又使SON经营者的收益最大化.     

No inventor is an island: Social connectedness and the geography of knowledge flows in the US

Do informal social ties connecting inventors across distant places promote knowledge flows between them? To measure informal ties, we use a new and direct index of social connectedness of regions based on aggregate Facebook friendships. We use a well-established identification strategy that relies on matching inventor citations with citations from examiners. Moreover, we isolate the specific effect of informal connections, above and beyond formal professional ties (co-inventor networks) and geographic proximity. We identify a significant and robust effect of informal ties on patent citations. Further, we find that the effect of geographic proximity on knowledge flows is entirely explained by informal social ties and professional networks. We also show that the effect of informal social ties on knowledge flows is greater for new entrepreneurs or ‘garage inventors’, for older or ‘forgotten’ patents, and for flows across distant technology fields. It has also become increasingly important over the last two decades.     

Contrastive and attentive graph learning for multi-view clustering

Graph-based multi-view clustering aims to take advantage of multiple view graph information to provide clustering solutions. The consistency constraint of multiple views is the key of multi-view graph clustering. Most existing studies generate fusion graphs and constrain multi-view consistency by clustering loss. We argue that local pair-view consistency can achieve fine-modeling of consensus information in multiple views. Towards this end, we propose a novel Contrastive and Attentive Graph Learning framework for multi-view clustering (CAGL). Specifically, we design a contrastive fine-modeling in multi-view graph learning using maximizing the similarity of pair-view to guarantee the consistency of multiple views. Meanwhile, an Att-weighted refined fusion graph module based on attention networks to capture the capacity difference of different views dynamically and further facilitate the mutual reinforcement of single view and fusion view. Besides, our CAGL can learn a specialized representation for clustering via a self-training clustering module. Finally, we develop a joint optimization objective to balance every module and iteratively optimize the proposed CAGL in the framework of graph encoder–decoder. Experimental results on six benchmarks across different modalities and sizes demonstrate that our CAGL outperforms state-of-the-art baselines.     

基于群体特征的社交僵尸网络检测方法

攻击者通过在社交网络中部署由大量社交僵尸账号组成的社交僵尸网络,对社交网络进行渗透,严重危害了社交网络和用户的信息安全.我们首次提出一种基于群体特征的社交僵尸网络检测方法.提取社交僵尸网络中账号注册时间集中、昵称相似和活跃时间一致3个群体特征,结合数据挖掘算法,设计一种社交僵尸网络的检测方法.在对新浪微博中48万个账号的检测实验中,检测出多个社交僵尸网络,共包含6 899个社交僵尸账号.较低的漏报率和误报率表明该方法对于社交僵尸网络和僵尸账号的检测是可行和有效的.     

一种针对在线社交网络的自动化僵尸账号攻击方案

分析僵尸账号对社交网络的主要威胁及社交网络对僵尸账号的检测机制,针对现有检测机制的不足设计规避检测的策略.使用该策略设计并实现一款利用僵尸账号对社交网络进行攻击的自动化工具.使用该工具对国内外最大的2个社交网站进行攻击测试.实验结果证明了策略与工具的有效性,并证明了社交网络针对僵尸账号的检测机制仍存在不足.     

异构网络中基于比例速率限制的网络选择和资源分配算法

针对UMTS/WLAN异构网络中的无线资源管理问题,提出基于比例速率限制的网络选择和资源分配算法.为保证用户间的公平性,将问题建模为带比例速率约束的系统吞吐量最大化问题.通过求解放松约束后的优化问题,得出用户网络选择与其到不同网络的可达速率之比相关的推论,并依此提出一种低复杂度的分布式算法.仿真结果表明,所提算法与原优化问题解的上界相比只有较小的性能损失,同时能有效保证用户间的公平性.     

Participatory action research and impact: an ecological ripples perspective

Assessment of the impact of varied forms of participatory research is enhanced by specific attention to the ripples, such work initiates in the social context. Ripples are defined as consequences either unintended or unanticipated by those carrying out the participatory research. Following a brief documentation of the range of reported ripples in reports describing participatory research, an ecological perspective drawing on the interdependence principle of ecological systems theory is presented as a framework for assessing impact by attending to ripples in the local context. Community asset mapping and social network analysis are described as examples of ways of describing and documenting environmental ripples, and strategies for both anticipating and reviewing ripples post hoc are discussed. The importance of developing cognitive maps of local ecology is stressed as critical to the assessment of the multiple potential impacts of participatory research.     

The UK National Arts Education Archive: Ideas and Imaginings

The National Arts Education Archive (NAEA) is housed and maintained by the Yorkshire Sculpture Park (YSP), and managed by YSP coordinators and educators with a well‐established volunteer programme. This year, 2017, as part of the celebrations of the YSP's 40th anniversary, the Archive will hold its own exhibition entitled Treasures Revealed: a collection of items selected by people who have been involved in the Archive, whether as donors, volunteers, researchers, artists, trustees or steering group members. In parallel with the exhibition, this article aims to give voice to a selection of individuals and groups associated with the Archive, discussing their interests and experiences of it, and their thoughts on its value and importance as a repository of arts education materials, ideals and practices. Our primary motivations were to consider these different voices in relation to the purpose, direction and relevance of the NAEA today. These exchanges raise fundamental questions and debates about what art education is and what it might become, and how these historical collections, and creative engagements with it, might help to shape our contemporary thinking.