Evolving neurocontrollers for the control of information diffusion in social networks

This paper presents a comparison of two Evolutionary Artificial Neural Network (EANN) variants acting as the autonomous control system for instances of the-Consensus Avoidance Problem ( θ-CAP). A novel variant of EANN is proposed by adopting characteristics of a well-performing heuristic into the structural bias of the neurocontroller. Information theoretic landscape measures are used to analyze the problem space as well as variants of the EANN. The results obtained indicate that the two neurocontroller variants learn distinctly different approaches to the θ-CAP, however, the newly proposed variant demonstrates improvements in both solution quality and execution time. A rampeddifficulty evolution scheme is demonstrated to be effective at creating higher quality results as compared to the standard scheme for EANNs. A correlation between the proposed instance difficulty and identifiable landscape characteristics is discovered as well

Vibrational investigations of lanthanide doped strontiumbarium niobate (SBN) crystals

Strontium barium niobate (Sr(0.5)Ba(0.5)Nb(2)O(6) and Sr(0.6)Ba(0.4)Nb(2)O(6)) single crystals doped with 1-2.5 mol% of the luminescent ions Eu(3+) and Er(3+) have been investigated using Raman and IR spectroscopy. The vibrational spectra of SBN crystals are dominated by broad and multi-component bands related to the internal vibrations of the NbO(6)(7-) octahedra. In order to interpret the experimental vibrational spectra of SBN crystals the quantum-chemical calculations (DFT) for the NbO(6)(7-) anion have been carried out. As a first approximation, the dynamics of isolated NbO(6)(7-) anions have been taken into account. The calculated vibrational frequencies for the free NbO(6)(7-) ion are in fair agreement with the frequencies of modes observed in experiment. The discrepancies are attributed to the distortion of the niobate octahedra in the actual crystal structure and to the presence of disorder and doping with impurity ions in SBN crystals

Towards the superlubricity of polymer–steel interfaces with ionic liquids and carbon nanotubes

Frictional losses are responsible for significant energy waste in many practical applications, and superlubricity with a coefficient of friction lower than 0.01 is the goal of tribologists. In this paper, metal-on-polymer contact was analysed and close to superlubricity conditions for this material configuration were explored. A new lubricant has been proposed hinge on the phosphorus-based ionic liquid and carbon nanotubes as thickeners. Additionally, carbon nanotube mesh was doped with copper nanoparticles that allowed for the close to superlubricity state in a mild steel/polymer contact configuration under low normal load conditions. The adsorption of phosphorus onto metallic and polymer surfaces has been reported in EDS analysis. The formulation of the new lubricant allowed for stable dispersion with a carbon nanotube content as low as 0.1% wt. The carbon nanotubes and Cu nanoparticles have been analysed using TEM and SEM imaging. A tribological test in a block-on-ring system has been carried out. The wear of material, topography, and surface free energy have been analysed along with SEM/EDS images to explore the underlying mechanisms of friction and wear

Lanthanide-doped strontium barium niobate (SBN) materials: A vibrational investigation

Vibrational Raman spectra have been measured for strontium barium niobate (Sr0.5Ba0.5Nb2O6, SBN50) single crystals and nanopowders doped with 1 mol% of the luminescent ions Eu3+ and Er3+. The nanocrystalline materials show slightly broader spectra with respect to the single crystals with the same composition. The presence of the Eu3+ and Er3+ ions at the 1 mol% doping level, and the present particle size (200 nm) do not appear to affect the ferro-to-paraelectric phase transition temperature typical of undoped SBN50 single crystals, as detected from anomalies in the dependence of the position of the Raman peak around 635 cm(-1) as a function of the temperature