95,429 research outputs found
Growing Self-organized Design of Efficient and Robust Complex Networks
A self-organization of efficient and robust networks is important for a
future design of communication or transportation systems, however both
characteristics are incompatible in many real networks. Recently, it has been
found that the robustness of onion-like structure with positive degree-degree
correlations is optimal against intentional attacks. We show that, by
biologically inspired copying, an onion-like network emerges in the incremental
growth with functions of proxy access and reinforced connectivity on a space.
The proposed network consists of the backbone of tree-like structure by
copyings and the periphery by adding shortcut links between low degree nodes to
enhance the connectivity. It has the fine properties of the statistically
self-averaging unlike the conventional duplication-divergence model,
exponential-like degree distribution without overloaded hubs, strong robustness
against both malicious attacks and random failures, and the efficiency with
short paths counted by the number of hops as mediators and by the Euclidean
distances. The adaptivity to heal over and to recover the performance of
networking is also discussed for a change of environment in such disasters or
battlefields on a geographical map. These properties will be useful for a
resilient and scalable infrastructure of network systems even in emergent
situations or poor environments.Comment: 10 pages, 14 figures, 3 tables, Proc. of 2014 IEEE 8th Int. Conf. on
Self-Adaptive and Self-Organizing Systems, pp.50-59.
http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7001000&tag=1. IEEE
Xplore Digital Library 201
A new design principle of robust onion-like networks self-organized in growth
Today's economy, production activity, and our life are sustained by social
and technological network infrastructures, while new threats of network attacks
by destructing loops have been found recently in network science. We inversely
take into account the weakness, and propose a new design principle for
incrementally growing robust networks. The networks are self-organized by
enhancing interwoven long loops. In particular, we consider the range-limited
approximation of linking by intermediations in a few hops, and show the strong
robustness in the growth without degrading efficiency of paths. Moreover, we
demonstrate that the tolerance of connectivity is reformable even from
extremely vulnerable real networks according to our proposed growing process
with some investment. These results may indicate a prospective direction to the
future growth of our network infrastructures.Comment: 21 pages, 10 figures, 1 tabl
Spatially self-organized resilient networks by a distributed cooperative mechanism
The robustness of connectivity and the efficiency of paths are incompatible
in many real networks. We propose a self-organization mechanism for
incrementally generating onion-like networks with positive degree-degree
correlations whose robustness is nearly optimal. As a spatial extension of the
generation model based on cooperative copying and adding shortcut, we show that
the growing networks become more robust and efficient through enhancing the
onion-like topological structure on a space. The reasonable constraint for
locating nodes on the perimeter in typical surface growth as a self-propagation
does not affect these properties of the tolerance and the path length.
Moreover, the robustness can be recovered in the random growth damaged by
insistent sequential attacks even without any remedial measures.Comment: 34 pages, 12 figures, 2 table
Contrasting Views of Complexity and Their Implications For Network-Centric Infrastructures
There exists a widely recognized need to better understand
and manage complex âsystems of systems,â ranging from
biology, ecology, and medicine to network-centric technologies.
This is motivating the search for universal laws of highly evolved
systems and driving demand for new mathematics and methods
that are consistent, integrative, and predictive. However, the theoretical
frameworks available today are not merely fragmented
but sometimes contradictory and incompatible. We argue that
complexity arises in highly evolved biological and technological
systems primarily to provide mechanisms to create robustness.
However, this complexity itself can be a source of new fragility,
leading to ârobust yet fragileâ tradeoffs in system design. We
focus on the role of robustness and architecture in networked
infrastructures, and we highlight recent advances in the theory
of distributed control driven by network technologies. This view
of complexity in highly organized technological and biological systems
is fundamentally different from the dominant perspective in
the mainstream sciences, which downplays function, constraints,
and tradeoffs, and tends to minimize the role of organization and
design
Seven properties of self-organization in the human brain
The principle of self-organization has acquired a fundamental significance in the newly emerging field of computational philosophy. Self-organizing systems have been described in various domains in science and philosophy including physics, neuroscience, biology and medicine, ecology, and sociology. While system architecture and their general purpose may depend on domain-specific concepts and definitions, there are (at least) seven key properties of self-organization clearly identified in brain systems: 1) modular connectivity, 2) unsupervised learning, 3) adaptive ability, 4) functional resiliency, 5) functional plasticity, 6) from-local-to-global functional organization, and 7) dynamic system growth. These are defined here in the light of insight from neurobiology, cognitive neuroscience and Adaptive Resonance Theory (ART), and physics to show that self-organization achieves stability and functional plasticity while minimizing structural system complexity. A specific example informed by empirical research is discussed to illustrate how modularity, adaptive learning, and dynamic network growth enable stable yet plastic somatosensory representation for human grip force control. Implications for the design of âstrongâ artificial intelligence in robotics are brought forward
ACCESS: An Inception Report
Imagine a world in which all groups of citizens coming together to realize some public benefit measure and communicate the character and consequences of their work. Imagine further that all those groups have adopted a common reporting system that enables their individual reports to be compared, thus creating powerful descriptions of the relative and collective performance of citizen association for public benefit. Imagine, too, that this common measuring and reporting carries across to all forms of public-private partnership and corporate social responsibility. This is the world envisioned by ACCESS.For the past 18 months a growing number of concerned actors have been meeting, studying, and testing opinion around one of the great structural weaknesses in the world's institutional infrastructure -- inefficient and weak social investment markets. This inception report sets out the results of this enquiry in the form of a proposal to establish a reporting standard for nonprofit organizations seeking to produce social, environmental and, increasingly, financial returns. The ACCESS Reporting standard is one important contribution to redressing a major global system weakness, but it is certainly not the only one. Nor is it one that can operate in isolation from other initiatives. Accordingly, the ACCESS proposed plan of work involves convening a global dialogue on NGO transparency, accountability and performance with the objective of promoting ACCESS and other practical solutions to the challenges of social investment and civil society accountability.This report sets out the background and rationale for these proposals. You will meet the ACCESS sponsors and pilot project partners. Parts of the report are descriptive and analytical but other parts are necessarily theoretical and technical in nature. We make no apology for this. Part of the reason that in 2003 the world does not yet have a reporting standard for social actors is that the theory and technique have not been mastered. For those with a strong orientation toward strategy and action, however, these aspects are presented as well
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
A contrasting look at self-organization in the Internet and next-generation communication networks
This article examines contrasting notions of self-organization in the Internet and next-generation communication networks, by reviewing in some detail recent evidence regarding several of the more popular attempts to explain prominent features of Internet structure and behavior as "emergent phenomena." In these examples, what might appear to the nonexpert as "emergent self-organization" in the Internet actually results from well conceived (albeit perhaps ad hoc) design, with explanations that are mathematically rigorous, in agreement with engineering reality, and fully consistent with network measurements. These examples serve as concrete starting points from which networking researchers can assess whether or not explanations involving self-organization are relevant or appropriate in the context of next-generation communication networks, while also highlighting the main differences between approaches to self-organization that are rooted in engineering design vs. those inspired by statistical physics
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