Journal of Computational and Applied Mathematics, 2011
The particle swarm optimization (PSO) technique is a powerful stochastic evolutionary algorithm t... more The particle swarm optimization (PSO) technique is a powerful stochastic evolutionary algorithm that can be used to find the global optimum solution in a complex search space. This paper presents a variation on the standard PSO algorithm called the rank based particle swarm optimizer, or PSO rank , employing cooperative behavior of the particles to significantly improve the performance of the original algorithm. In this method, in order to efficiently control the local search and convergence to global optimum solution, the γ best particles are taken to contribute to the updating of the position of a candidate particle. The contribution of each particle is proportional to its strength. The strength is a function of three parameters: strivness, immediacy and number of contributed particles. All particles are sorted according to their fitness values, and only the γ best particles will be selected. The value of γ decreases linearly as the iteration increases. A time-varying inertia weight decreasing non-linearly is introduced to improve the performance. PSO rank is tested on a commonly used set of optimization problems and is compared to other variants of the PSO algorithm presented in the literature. As a real application, PSO rank is used for neural network training. The PSO rank strategy outperformed all the methods considered in this investigation for most of the functions. Experimental results show the suitability of the proposed algorithm in terms of effectiveness and robustness.
2012 45th Hawaii International Conference on System Sciences, 2012
It has been argued that hierarchical 'command and control' leadership is required to co... more It has been argued that hierarchical 'command and control' leadership is required to coordinate massive and rapid military or disaster response. Against this, the concept of leaderless 'social media revolution' refers to the wide-spread use of Web 2.0 social media by ordinary citizens to transform the public sphere and engage in collective political action, including coordinating massive and rapid protests against government. However, conceptual and empirical research efforts remain scarce to date. This research draws on the emergent perspective on causal agency in effecting change in social systems to examine our research proposition that the interactive effects of networked publics and social media would transform the public sphere for conversation when democracy is much desired by the citizens. We then discuss our online survey results and key findings of Iranian Face book users' views and experiences before, during, and after the 2009 Presidential electi...
Journal of Computational and Applied Mathematics, 2011
The particle swarm optimization (PSO) technique is a powerful stochastic evolutionary algorithm t... more The particle swarm optimization (PSO) technique is a powerful stochastic evolutionary algorithm that can be used to find the global optimum solution in a complex search space. This paper presents a variation on the standard PSO algorithm called the rank based particle swarm optimizer, or PSO rank , employing cooperative behavior of the particles to significantly improve the performance of the original algorithm. In this method, in order to efficiently control the local search and convergence to global optimum solution, the γ best particles are taken to contribute to the updating of the position of a candidate particle. The contribution of each particle is proportional to its strength. The strength is a function of three parameters: strivness, immediacy and number of contributed particles. All particles are sorted according to their fitness values, and only the γ best particles will be selected. The value of γ decreases linearly as the iteration increases. A time-varying inertia weight decreasing non-linearly is introduced to improve the performance. PSO rank is tested on a commonly used set of optimization problems and is compared to other variants of the PSO algorithm presented in the literature. As a real application, PSO rank is used for neural network training. The PSO rank strategy outperformed all the methods considered in this investigation for most of the functions. Experimental results show the suitability of the proposed algorithm in terms of effectiveness and robustness.
2012 45th Hawaii International Conference on System Sciences, 2012
It has been argued that hierarchical 'command and control' leadership is required to co... more It has been argued that hierarchical 'command and control' leadership is required to coordinate massive and rapid military or disaster response. Against this, the concept of leaderless 'social media revolution' refers to the wide-spread use of Web 2.0 social media by ordinary citizens to transform the public sphere and engage in collective political action, including coordinating massive and rapid protests against government. However, conceptual and empirical research efforts remain scarce to date. This research draws on the emergent perspective on causal agency in effecting change in social systems to examine our research proposition that the interactive effects of networked publics and social media would transform the public sphere for conversation when democracy is much desired by the citizens. We then discuss our online survey results and key findings of Iranian Face book users' views and experiences before, during, and after the 2009 Presidential electi...
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