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.     

基于TM遥感图像的流域地貌研究

利用不同地物在同一波段或相同地物在不同波段具有不同色调的变化规律，以奉化江流域为例，探讨了遥感技术在流域地貌研究中的应用。根据遥感图像成像规律以及不同地质地貌景观类型在TM图像上所显示的不同解译标志和展布特征，对研究区水系的发育、地质构造与地表物质对流域地貌形成的作用和影响等作了一定的分析与探索，获得了较为满意的结果。     

基于贝叶斯正则化BP神经网络的上市公司信用评价研究

在神经网络训练中引入贝叶斯正则化以提高模型的推广能力。通过与未使用提高推广能力方法和使用提前停止法两种情况进行比较,表明基于贝叶斯正则化的BP神经网络模型在上市公司信用评价中的推广能力有显著的提高。     

Community Networks: Rules of Behavior and Social Structure

This article investigates the intertwining relationships between the Gemeinschaft and the Gesellschaft dimension of a community network (CN)—that is, of a virtual community whose members' common interest is a locality, in our case the city of Milan, Italy. The article looks through the experience of the last 7 years of life on RCM—the Milan Community Network—to reflect on the role that the sharing of rules of behavior has on the evolution of social structure in a virtual community. It identifies three phases of development—the design phase, the first growth phase, and the most recent phase—and presents the social structure set up to guarantee governance of the CN. The conclusions show that the third phase is not an actual stable state, as the continuous evolution of the societal and technological context requires continuous redesign of the CN itself in order to meet the renewed demands of a new context.