Influence fast or later: Two types of influencers in social networks

In real-world networks, there usually exist a small set of nodes that play an important role in the structure and function of networks. Those vital nodes can influence most of other nodes in the network via a spreading process. While most of the existing works focused on vital nodes that can maximize the spreading size in the final stage, which we call final influencers, recent work proposed the idea of fast influencers, which emphasizes nodes' spreading capacity at the early stage. Despite the recent surge of efforts in identifying these two types of influencers in networks, there remained limited research on untangling the differences between the fast influencers and final influencers. In this paper, we firstly distinguish the two types of influencers: fast-only influencers and final-only influencers. The former is defined as individuals who can achieve a high spreading effect at the early stage but lose their superiority in the final stage, and the latter are those individuals that fail to exhibit a prominent spreading performance at the early stage but influence a large fraction of nodes at the final stage. Further experiments are based on eight empirical datasets, and we reveal the key differences between the two types of influencers concerning their spreading capacity and the local structures. We also analyze how network degree assortativity influences the fraction of the proposed two types of influencers. The results demonstrate that with the increase of degree assortativity, the fraction of the fast-only influencers decreases, which indicates that more fast influencers tend to keep their superiority at the final stage. Our study provides insights into the differences and evolution of different types of influencers and has important implications for various empirical applications, such as advertisement marketing and epidemic suppressing.     

在不同议题上频繁主动出击

<正>习近平这一年多来的周边外交举措很多,而且还在演化过程中,此处仅谈几点不成熟的看法。第一,习近平时代有一个重要的特点:对于外交的关注和投入显著增大。2014年中国举办了两次主场外交(亚信会议和APEC会议),习主席一年多来共出访11次(非洲一次,拉美一次,欧洲一次,北美一次,其他七次都在周边),一共到访了30多个国家。看领导人对一个问题重视不重视,就看他在这个问题上花了多少时间,这一年多来习主席在外交上的     

对前次(2月4日)中法关系预报的检验

今年2月4日,我们预报了中法关系未来三个月的变化趋势(见本刊第4期),在此我们根据以往三个月发生的事件对这一预报进行检验。一、2004年2-4月中法关系的基本事件及其走势2月,中法关系平稳不变。该月双边关系中没有发生有影响的负面事件。双边关系中的主要正面事件是法国努力推动欧盟解除对华军售禁令,但未能达到预期效果。3月,中法关系小幅微升。该月双边关系中的主要正面事件是:中国政府特使、外交部副部长戴秉国访法;中法海军举行两军首次联合军事演习,这次演习是中国海军迄今与外国海军之间举行的内容最为丰富、规模最大的一次联合军事演…     

快速傅里叶变换在卫星重力梯度测量中的应用

本文将混合基快速傅里叶变换应用于卫星重力梯度测量数据处理。从已知位系数求重力梯度值和已知全球重力梯度值反求位系数两方面进行了数值模拟计算。数值结果表明：引入ＦＦＴ技术后，计算速度获得了极大的提高，并且随着所考虑的阶数ｎ的增加，速度提高更快。当ｎ＝５０，已比直接计算快近１０倍，ｎ＝１２０，则快３０多倍。     

对6月4日中印关系预测的检验

印度国大党于今年5月赢得大选胜利,曼莫汉·辛格出任印度总理,并组织了新政府。中印双方都希望印度新政府能加快中印关系的改善。今年6月4日,我们对中印关系未来三个月的发展变化趋势进行了预测(见第12期)。现在我们对此次预测的准确性进行简单的评估。一、2004年6-8月中印关系的基本事件及走势6月,中印关系保持不变,该月较重要的正面事件是:6月21日,外交部长李肇星在青岛分别会见了前来参加亚洲合作对话第三次外长会议的印度外长辛格及其他国家外长。7月,中印关系保持不变,该月较重要的正面事件是:7月2日,中国外交部长李肇星在雅加达出席了…     

纠缠判据对分析量子保密通信安全性的作用

研究何广强等人定义的参数F对分析量子保密通信安全性的作用。结果表明，参数能够用来描述两模纠缠系统的纠缠度量，可以用来作为纠缠判据。     

微量进样器校准方法

建立了微量进样器校准方法。采用衡量法纯水和水银两种不同介质和分光光度法研究微量进样器的校准,通过对不同方法进行比较分析,得出最佳校准方法是采用纯水介质的衡量法。校准条件:控制环境温度在(20±5)℃,保证水温与室温温差不超过±2℃,相对湿度控制在30%～60%,采取防蒸发措施。采用该操作方法能够完全适用于微量进样器的校准。     

高含盐油藏水驱储层参数变化机理及规律研究

通过岩心驱替以及砂岩微观孔隙模型驱替实验,研究了高含盐油藏水驱储层参数变化机理和规律。运用先进的支持向量机方法对驱替实验结果进行处理,完成了储层渗透率变化规律的定量描述。研究结果表明,高含盐油藏储层参数变化呈多元非线性函数关系,变化规律复杂;渗透率变化存在临界值,大于临界值时,渗透率随着驱替速度、驱替量和含盐量的增加而增大,小于临界值时,渗透率随着驱替速度、驱替量和含盐量的增加而减小;注入水性质会对参数变化过程有影响,而对最终变化结果无影响;盐的溶解是储层参数变化的根本原因,岩石颗粒的脱落和运移是储层参数变化的直接原因。     

DISCRIMINATION OF Moraxella AND Legionella pneumophila BY GAS CHROMATOGRAPHY OF WHOLE-CELL FATTY ACIDS

Whole-cell fatty acid profiles of 36 strains of Moraxella and its related bacteria, and 13 strainsof Legionella pneumophila were obtained by capillary gas chromatography (GC). Some component peaksin these profiles were analyzed by gas chromatography-mass spectrometry (GC-MS). Hierarchical clus-tering analysis of these bacterial fatty acid patterns was done with a microcomputer. Results showedthat these were some obvious differences between the two new species of Moraxella isolated in China,i.e. M. amylolytica and M. nanchang, and the currently established reference strains of this genus. Themajor fatty acids of these two new species were the isomers of pentadecanoic (C_(15:0)) acids. Theprofiles of L. pneumophila NJ 8331 and LDB 4_a recently isolated in China were essentially similar tothose of international reference strains type 1-8 (CDC, USA), which contained mainly 16-carbon (C_(16))acids, whereas another isolate LDB 4b was obviously dissimilar. The results of this method of discrim-ination and of t     

亚高原地区弹射救生控制技术研究

为实现隔行扫描到逐行扫描的视频扫描格式转换,提出了一种时空权重和边缘自适应的去隔行算法,主要包括运动估计、小角度边缘搜索、时空权重计算、自适应插值等。该算法通过4场相邻像素的最大灰度变化与运动阈值比较实现对当前像素的运动估计,采用自适应搜索半径和并行搜索树的方法实现小角度边缘检测,并且增加对半像素边缘的考虑实现最小6°边缘的检测,最后通过时空权重自适应的插值算法实现去隔行处理,取得很好的处理效果。