1,063 research outputs found
Self-organized Emergence of Navigability on Small-World Networks
This paper mainly investigates why small-world networks are navigable and how
to navigate small-world networks. We find that the navigability can naturally
emerge from self-organization in the absence of prior knowledge about
underlying reference frames of networks. Through a process of information
exchange and accumulation on networks, a hidden metric space for navigation on
networks is constructed. Navigation based on distances between vertices in the
hidden metric space can efficiently deliver messages on small-world networks,
in which long range connections play an important role. Numerical simulations
further suggest that high cluster coefficient and low diameter are both
necessary for navigability. These interesting results provide profound insights
into scalable routing on the Internet due to its distributed and localized
requirements.Comment: 3 figure
Collective navigation of complex networks: Participatory greedy routing
Many networks are used to transfer information or goods, in other words, they
are navigated. The larger the network, the more difficult it is to navigate
efficiently. Indeed, information routing in the Internet faces serious
scalability problems due to its rapid growth, recently accelerated by the rise
of the Internet of Things. Large networks like the Internet can be navigated
efficiently if nodes, or agents, actively forward information based on hidden
maps underlying these systems. However, in reality most agents will deny to
forward messages, which has a cost, and navigation is impossible. Can we design
appropriate incentives that lead to participation and global navigability?
Here, we present an evolutionary game where agents share the value generated by
successful delivery of information or goods. We show that global navigability
can emerge, but its complete breakdown is possible as well. Furthermore, we
show that the system tends to self-organize into local clusters of agents who
participate in the navigation. This organizational principle can be exploited
to favor the emergence of global navigability in the system.Comment: Supplementary Information and Videos:
https://koljakleineberg.wordpress.com/2016/11/14/collective-navigation-of-complex-networks-participatory-greedy-routing
Organic Design of Massively Distributed Systems: A Complex Networks Perspective
The vision of Organic Computing addresses challenges that arise in the design
of future information systems that are comprised of numerous, heterogeneous,
resource-constrained and error-prone components or devices. Here, the notion
organic particularly highlights the idea that, in order to be manageable, such
systems should exhibit self-organization, self-adaptation and self-healing
characteristics similar to those of biological systems. In recent years, the
principles underlying many of the interesting characteristics of natural
systems have been investigated from the perspective of complex systems science,
particularly using the conceptual framework of statistical physics and
statistical mechanics. In this article, we review some of the interesting
relations between statistical physics and networked systems and discuss
applications in the engineering of organic networked computing systems with
predictable, quantifiable and controllable self-* properties.Comment: 17 pages, 14 figures, preprint of submission to Informatik-Spektrum
published by Springe
Hidden geometric correlations in real multiplex networks
Real networks often form interacting parts of larger and more complex
systems. Examples can be found in different domains, ranging from the Internet
to structural and functional brain networks. Here, we show that these multiplex
systems are not random combinations of single network layers. Instead, they are
organized in specific ways dictated by hidden geometric correlations between
the individual layers. We find that these correlations are strong in different
real multiplexes, and form a key framework for answering many important
questions. Specifically, we show that these geometric correlations facilitate:
(i) the definition and detection of multidimensional communities, which are
sets of nodes that are simultaneously similar in multiple layers; (ii) accurate
trans-layer link prediction, where connections in one layer can be predicted by
observing the hidden geometric space of another layer; and (iii) efficient
targeted navigation in the multilayer system using only local knowledge, which
outperforms navigation in the single layers only if the geometric correlations
are sufficiently strong. Our findings uncover fundamental organizing principles
behind real multiplexes and can have important applications in diverse domains.Comment: Supplementary Materials available at
http://www.nature.com/nphys/journal/v12/n11/extref/nphys3812-s1.pd
Navigable networks as Nash equilibria of navigation games
Common sense suggests that networks are not random mazes of purposeless connections,
but that these connections are organized so that networks can perform their functions well.
One function common to many networks is targeted transport or navigation. Here, using
game theory, we show that minimalistic networks designed to maximize the navigation
efficiency at minimal cost share basic structural properties with real networks. These
idealistic networks are Nash equilibria of a network construction game whose purpose is to
find an optimal trade-off between the network cost and navigability. We show that these
skeletons are present in the Internet, metabolic, English word, US airport, Hungarian road
networks, and in a structural network of the human brain. The knowledge of these skeletons
allows one to identify the minimal number of edges, by altering which one can efficiently
improve or paralyse navigation in the network
Rural small firms' website quality in transition and market economies
Purpose
– The purpose of this paper is to investigate website quality in rural firms in four countries, by using Gonzalez and Palacios's Web Assessment Index (WAI). There is an assertion in the literature that quality is lower amongst rural firms than urban firms, and lower amongst small firms than large firms. The disadvantages of lack of access to skills and economic peripherality in rural areas are attributed to this. Concurrently, there is reason to surmise that the websites of firms in transition economies may be higher quality than those in market economies. The paper aims to explore websites in distinct rural regions to investigate if variation occurs.
Design/methodology/approach
– To evaluate website quality the WAI was applied to a sample of 60 rural firms representing 15 each in Scotland, New Zealand, Southern Russia and Hunan Province in China. Analysis of the categorical data was performed using a variety of established methods.
Findings
– The WAI is of use in terms of website quality management. Additionally, comparisons between the quality of websites in the sample of small rural firms with those of large firms in previous studies support the contention that large firms generally have better quality websites. Results also illustrate that there are some differences in website quality between rural small businesses in the different locations. In particular, small rural firms in Hunan Province in China had websites of observable better quality than those elsewhere. The authors conclude that skills, knowledge and infrastructure have a bearing on the sophistication of small firms' websites.
Research limitations/implications
– Implications include that variation in the rural economy by region prevails as the rural economy is not, as often implied, a homogeneous concept.
Practical implications
– There are implications in terms of exploring the effects of regulation, culture and infrastructure on rural small to medium-sized enterprises (SMEs). The internet may indeed contribute to rural economies, but only insofar as it is facilitated by infrastructure and access to skills, and by culture and perceived usefulness by business owners.
Originality/value
– The paper contributes to the understanding of rural entrepreneurship as a heterogeneous concept by comparing practice in four distinct rural regions. It also adds weight to the emerging identification of exogenous factors as being at least as much a factor in determining the use of ICT in rural SMEs as endogenous motivations, skills and resources.
</jats:sec
Network Geometry
Networks are finite metric spaces, with distances defined by the shortest paths between nodes. However, this is not the only form of network geometry: two others are the geometry of latent spaces underlying many networks and the effective geometry induced by dynamical processes in networks. These three approaches to network geometry are intimately related, and all three of them have been found to be exceptionally efficient in discovering fractality, scale invariance, self-similarity and other forms of fundamental symmetries in networks. Network geometry is also of great use in a variety of practical applications, from understanding how the brain works to routing in the Internet. We review the most important theoretical and practical developments dealing with these approaches to network geometry and offer perspectives on future research directions and challenges in this frontier in the study of complexity
- …