具有时变时滞的复杂动力学网络的同步控制

研究了具有时变耦合时滞的复杂动力学网络的同步控制问题.设计了一个线性反馈控制器,通过构造Lyapunov函数,证明了该控制器能够使具有时变耦合时滞的复杂动力学网络实现渐近同步.数值仿真结果也证实了该控制器的有效性.     

Shared contexts and triadic closure in core discussion networks

This paper inquires into structural explanations for triadic closure in networks of confidants with whom one discusses important personal matters. Building upon the assumption that meeting opportunities affect network characteristics, we primarily argue that the social contexts in which network members meet, substantially affect triadic closure. The main empirical findings are (a) that about sixty percent of the triads in core discussion networks are closed triads, which also means that a substantial part of one's strong relations is unconnected, and (b) that meeting network members in the same social contexts is an important condition for, but certainly does not guarantee triadic closure. Importantly, the specific characteristics of social contexts explain why sharing certain contexts positively affects triadic closure, while sharing other contexts does not.     

Calling social capital: An analysis of the determinants of success on the TV quiz show “Who Wants to Be a Millionaire?”

This paper analyzes the determinants of successful participation of candidates on the well known television quiz show “Who Wants to Be a Millionaire?”. Our study includes a survey of 660 contestants who participated in the German version of the show between 1999 and 2007. We are particularly interested in two hypotheses. The first hypothesis refers to the assumed advantage of social capital. Contestants on the show have the option of calling a friend (the phone-a-friend lifeline) whom they select from their personal networks. The person chosen to be the phone-a-friend lifeline should be especially helpful if the contestant has a large network of able contacts from which to choose. Second, according to human capital theory the participants’ education should increase the chances of success and should lead on average to higher payoffs. Since contestants on the show can answer questions correctly mainly on the basis of their knowledge and since other characteristics of the candidates are irrelevant, estimates of the human capital effect are not affected by other possible causes suggested by signaling theory. Thus, our analysis is an assessment of the effects of social capital and human capital on the show.     

容忍延迟网络中基于生灭模型的消息控制方法

提出了在多拷贝传递的基础上增加消息拷贝消除机制,合理地控制了网络中的消息拷贝数。在网络中根据节点相遇时消息拷贝数发生变化的特性,构造了消息拷贝数的离散时间的马尔可夫链,建立生灭模型,进一步验证并得出了平稳分布。通过仿真实验比较,相遇次数与时间基本上是线性关系,与理论模型极为相近。与传染路由比较,采用拷贝消除机制网络中的消息拷贝数有了明显的减少,消息成功传递率达到90%,适当增加延迟时间,能够达到100%。消息拷贝数的平稳分布与仿真实验中基本一致。     

复杂性范式视野下的复杂网络研究及其意义

在对复杂性的探索过程中,科学研究的思维方式经历了由“还原论范式”到“整体论范式”再到“复杂性范式”的转换,复杂网络理论是近年来在探索复杂性问题上的一个新的研究视角。本文对复杂性研究和复杂网络理论的研究进展作了梳理,对二者的关系和意义进行了探讨,结合实例分析了复杂网络模型方法模拟复杂系统涌现的过程,在肯定这一方法的同时,也指出了该方法的局限性。     

QQ群好友关系的复杂网络研究

本文抽样构建了QQ群好友关系的复杂网络模型,并对其属性及动力机制进行了分析,然后通过对微软俱乐部好友群的问卷调查,讨论中心度对组织活动的意义。得出QQ群好友网络具有稀疏性、增长性与小世界性,以及成员的中心度越大,参与活动的力度与影响力越大的结论。     

Regional rail planning; a study of the importance of ‘steering’ and ‘pragmatism’ in stakeholder networks

This paper investigates the significance of networks in regional rail planning and how these networks can help regional planners meet the needs of local stakeholders. The research question focuses on the identification of the relative importance of three core factors in regional planning – communicative discourse, steering and environment. A case study of the Highlands and Islands region of Scotland was studied, with qualitative data analysed by triangulation through semi-structured interviews and social network analysis (SNA).     

Subcontracting and the incidence of change orders in procurement contracts

In public procurement, most contracts are renegotiated ex post and involve subcontractors. We examine whether there is a causal link between subcontractor use and the incidence of change orders to amend the original scope of a project. Since subcontracting is likely related to unobserved project complexity, we use a novel IV, the predicted level of subcontracting from a method modeled after Christakis et al. (2010), to estimate the likelihood of renegotiation. The results establish that subcontractors are associated with an increased likelihood of change orders as well as a higher dollar amount renegotiated.     

Not necessarily a place: How mobile transnational online workers (digital nomads) construct and experience ‘home’

This article adds to current research on mobile transnational online workers (digital nomads) who travel the world in search of a holistic lifestyle that balances work and leisure. Using Kannisto's (2014) and D'Andrea's (2007) work on ‘global nomads’ as a theoretical lens and Nowicka's (2007) research on mobile professionals as a guide, I discuss the multiple meanings of ‘home’ for digital nomads who stayed in Chiang Mai, Thailand, in 2019. I will show that people feel at home when travelling with a loved one or by surrounding themselves with objects of emotional value. Furthermore, digital nomads create a feeling of being at home by connecting with their family via social media and video calling apps, while at the same time keeping them at a comfortable distance. Finally, some digital nomads envision an idealized ‘home base’ that is defined by social relations and not necessarily by the geography or amenities of a place.     

Geographies of Social Networks: Meetings,Travel and Communications

The past decade has seen striking increases in travel and in communications at‐a‐distance through mobile phone calls, text messaging and emailing. People in prosperous societies are both travelling and communicating more to connect with absent others. People can travel, relocate and migrate and yet still be connected with friends and family members ‘back home’. So, increasingly, people who are near emotionally may be geographically very far away; yet they are only a journey, email or a phone call away. In this article we attempt to examine how such strong ties are spatially distributed and sustained through specific geographies of travel, meetings and communications. How often do strong ties meet, talk at‐at‐distance and write, and to what degree does distance determine regularity? To what extent are communications enhancing and/or substituting for physical travel? We examine in particular to what degree far‐flung ties and emotional networking at‐a‐distance are characteristic of many people other than the transnational ‘elites’ and ‘underprivileged’ migrants. We consider the notion of ‘network capital’.