Community structure can be observed in many natural, biological and social networks. Studies sug- gest that these communities may have organized in a hi- erarchical manner while some communities overlap with others. This paper introduces an algorithm to detect such hierarchical and overlapping community structures in net- works based on the concept of maximal cliques. It intro- duces an alternate modularity for evaluating overlapping community structures. Unlike existing algorithms for de- tecting hierarchical and overlapping community structures, the new algorithm is free of parameter tuning and random seeds. Experiments conducted on two real-world networks show that this algorithm is capable of providing satisfac- tory and consistent results.
No abstract is provided for this article.
The origins of voice communication technologies are typically narrated through a sequence of industrial and scientific milestones culminating in today’s global digital networks. Yet, early developments in telephony also reveal deeply human motivations and socially embedded forms of innovation. This article compares Antonio Meucci’s nineteenth-century “telettrofono”—a low-energy, household communication device conceived to assist his ailing wife—with today’s sophisticated smartphone-based infrastructures. By examining these two endpoints of the telecommunication continuum, the article explores how communication technologies evolved from intimate human-centered solutions to complex, energy-intensive systems. It also discusses the ethics of recognition within institutional frameworks such as the IEEE Milestones Program. The goal is not to reopen historical disputes, but to promote a socially aware and inclusive memory of technological innovation, consistent with IEEE’s mission to advance technology for humanity.
In this paper, the Parameter Switching (PS) algorithm is used to numerically approximate attractors of a Hopfield Neural Network (HNN) system. The PS algorithm is a convergent scheme designed for approximating the attractors of an autonomous nonlinear system, depending linearly on a real parameter. Aided by the PS algorithm, it is shown that every attractor of the HNN system can be expressed as a convex combination of other attractors. The HNN system can easily be written in the form of a linear parameter dependence system, to which the PS algorithm can be applied. This work suggests the possibility to use the PS algorithm as a control-like or anticontrol-like method for chaos.
No abstract is provided for this article.
The complex topology of a network determines its dynamics. The world economy is now internationally connected through a globalization process of trading. The complex dynamical behaviors of the world economy have been studied as a dynamical system, but there does not seem to be any consideration of the effect of dynamics on the world trade network. In this paper, we attempt such a study and present the scale-free features of the degree distribution, as well as wealth and resource distributions on the World Trade Web (WTW). Moreover, the synchronization phenomenon of economic cycles on the WTW due to its scale-free features is discussed in detail.
This paper reports a new four-dimensional continuous autonomous chaotic system, in which each equation in the system contains a 3-term cross product. Basic properties of the system are analyzed by means of Lyapunov exponents and bifurcation diagrams.
A Cournot duopoly, with a bounded inverse demand function and different constant marginal production costs, can be modeled as a discrete-time dynamical system, which exhibits complex bifurcating and chaotic behaviors. Based on some essential features of the model, we show how bifurcation and chaos can be controlled via the delayed feedback control method. We then propose and evaluate an adaptive parameter-tuning algorithm for control. In addition, we discuss possible economic implications of the chaos control strategies described in the paper.
This paper introduces the concept of Lyapunov V-stability for complex dynamical networks. Under the new framework, each dynamical node is associated with a passivity degree, which indicates to what extent an effort is required for stabilizing the node. From this approach, the network stability problem is converted to measuring the negative definiteness of one simple matrix that characterizes the topology of the network. Pinning control is then suggested and investigated based on the new V-stability formulation. As an illustrative example, a network with different node dynamics and non-uniform coupling strengths is simulated to verify the analytic results. Moreover, a comparison study for three different kinds of networks is provided to further illustrate the novelty and efficacy of the proposed V-stability criterion and stabilization scheme.
No abstract is provided for this article.
This letter reports the finding of a new chaotic attractor in a simple three-dimensional autonomous system, which connects the Lorenz attractor and Chen's attractor and represents the transition from one to the other.
This paper studies the bifurcations of phase portraits for the regularized Saint-Venant equation (a two-component system), which appears in shallow water theory, by using the theory of dynamical systems and singular traveling wave techniques developed in [Li & Chen, 2007] under different parameter conditions in the two-parameter space. Some explicit exact parametric representations of the solitary wave solutions, smooth periodic wave solutions, periodic peakons, as well as peakon solutions, are obtained. More interestingly, it is found that the so-called [Formula: see text]-traveling wave system has a family of pseudo-peakon wave solutions, and their limiting solution is a peakon solution. In addition, it is found that the [Formula: see text]-traveling wave system has two families of uncountably infinitely many solitary wave solutions and compacton solutions.
