The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Tomasz Kulpa - One of the best experts on this subject based on the ideXlab platform.
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IJCCI (Selected Papers) - Particle Stability Time in the Stochastic Model of PSO.
Studies in Computational Intelligence, 2019Co-Authors: Krzysztof Trojanowski, Tomasz KulpaAbstract:Stability properties of a Particle in the stochastic models of PSO are a subject of presented analysis. Measures of a number of Particle steps necessary to reach an equilibrium state, particularly, generalized weak versions of measures: Particle convergence expected time (pcet) and the Particle location variance convergence time (pvct) are developed. A new measure, namely Particle Stability time, is also proposed. For all the measures graphs of estimated and recorded values are presented. Finally, an adaptation of expected running time (ERT) measure is proposed which can be applied for identification of convergence regions in the parameters space.
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Particle Stability Time in the Stochastic Model of PSO
Computational Intelligence, 2019Co-Authors: Krzysztof Trojanowski, Tomasz KulpaAbstract:Stability properties of a Particle in the Trojanowski, Krzysztof stochastic models of PSO are a subject of presented analysis. Measures of a number of Particle steps necessary to reach an equilibrium state, particularly, generalized weak versions of measures: Particle convergence expected time ( pcet ) and the Particle location variance convergence time ( pvct ) are developed. A new measure, namely Particle Stability time, is also proposed. For all the measures graphs of estimated and recorded values are presented. Finally, an adaptation of expected running time (ERT) measure is proposed which can be applied for identification of convergence regions in the parameters space.
Jane Pratt - One of the best experts on this subject based on the ideXlab platform.
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Trapped Particle Stability for the kinetic stabilizer
Nuclear Fusion, 2011Co-Authors: Herbert L Berk, Jane PrattAbstract:A kinetically stabilized axially symmetric tandem mirror (KSTM) uses the momentum flux of low-energy, unconfined Particles that sample only the outer end-regions of the mirror plugs, where large favourable field-line curvature exists. The window of operation is determined for achieving magnetohydrodynamic (MHD) Stability with tolerable energy drain from the kinetic stabilizer. Then MHD stable systems are analysed for Stability of the trapped Particle mode. This mode is characterized by the detachment of the central-cell plasma from the kinetic-stabilizer region without inducing field-line bending. Stability of the trapped Particle mode is sensitive to the electron connection between the stabilizer and the end plug. It is found that the Stability condition for the trapped Particle mode is more constraining than the Stability condition for the MHD mode, and it is challenging to satisfy the required power constraint. Furthermore, a severe power drain may arise from the necessary connection of low-energy electrons in the kinetic stabilizer to the central region.
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trapped Particle Stability for the kinetic stabilizer
arXiv: Plasma Physics, 2011Co-Authors: Herbert L Berk, Jane PrattAbstract:A kinetically stabilized axially symmetric tandem mirror (KSTM) uses the momentum flux of low-energy, unconfined Particles that sample only the outer end-regions of the mirror plugs, where large favorable field-line curvature exists. The window of operation is determined for achieving MHD Stability with tolerable energy drain from the kinetic stabilizer. Then MHD stable systems are analyzed for Stability of the trapped Particle mode. This mode is characterized by the detachment of the central-cell plasma from the kinetic stabilizer region without inducing field-line bending. Stability of the trapped Particle mode is sensitive to the electron connection between the stabilizer and the end plug. It is found that the Stability condition for the trapped Particle mode is more constraining than the Stability condition for the MHD mode, and it is challenging to satisfy the required power constraint. Furthermore a severe power drain may arise from the necessary connection of low-energy electrons in the kinetic stabilizer to the central region.
Oliver Kröcher - One of the best experts on this subject based on the ideXlab platform.
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structural reversibility and nickel Particle Stability in lanthanum iron nickel perovskite type catalysts
Chemsuschem, 2017Co-Authors: Patrick Steiger, Renaud Delmelle, Debora Foppiano, Lorenz Holzer, Andre Heel, Maarten Nachtegaal, Oliver KröcherAbstract:Perovskite-type oxides have shown the ability to reversibly segregate precious metals from their structure. This reversible segregation behavior was explored for a commonly used catalyst metal, Ni, to prevent Ni sintering, which is observed on most catalyst support materials. Temperature-programmed reduction, X-ray diffraction, X-ray absorption spectroscopy, electron microscopy, and catalytic activity tests were used to follow the extent of reversible Ni segregation. LaFe1-xNixO3-delta (0 <= x <= 0.2) was synthesized using a citrate-based solution pro-cess. After reduction at 600 degrees C, metallic Ni Particles were displayed on the perovskite surfaces, which were active towards the hydrogenation of CO2. The overall Ni reducibility was proportional to the Ni content and increased from 35% for x=0.05 to 50% for x=0.2. Furthermore, Ni could be reincorporated reversibly into the perovskite lattice during reoxidation at 650 degrees C. This could be exploited for catalyst regeneration under conditions under which impregnated materials such as Ni/ LaFeO3-delta and Ni/Al2O3 suffer from sintering.
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Structural Reversibility and Nickel Particle Stability in Lanthanum Iron Nickel Perovskite-Type Catalysts.
ChemSusChem, 2017Co-Authors: Patrick Steiger, Renaud Delmelle, Debora Foppiano, Lorenz Holzer, Andre Heel, Maarten Nachtegaal, Oliver Kröcher, Davide FerriAbstract:Perovskite-type oxides have shown the ability to reversibly segregate precious metals from their structure. This reversible segregation behavior was explored for a commonly used catalyst metal, Ni, to prevent Ni sintering, which is observed on most catalyst support materials. Temperature-programmed reduction, X-ray diffraction, X-ray absorption spectroscopy, electron microscopy, and catalytic activity tests were used to follow the extent of reversible Ni segregation. LaFe1-xNixO3-delta (0
Younsoo Bae - One of the best experts on this subject based on the ideXlab platform.
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Block Copolymer Cross-Linked Nanoassemblies Improve Particle Stability and Biocompatibility of Superparamagnetic Iron Oxide NanoParticles
Pharmaceutical research, 2012Co-Authors: Mo Dan, Daniel Scott, Peter A. Hardy, Robert J. Wydra, J. Zach Hilt, Robert A. Yokel, Younsoo BaeAbstract:Purpose To develop cross-linked nanoassemblies (CNAs) as carriers for superparamagnetic iron oxide nanoParticles (IONPs).
Andries P. Engelbrecht - One of the best experts on this subject based on the ideXlab platform.
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ANTS Conference - Stability Analysis of the Multi-objective Multi-guided Particle Swarm Optimizer
Lecture Notes in Computer Science, 2018Co-Authors: Christopher Wesley Cleghorn, Christiaan Scheepers, Andries P. EngelbrechtAbstract:At present Particle swarm optimizers (PSO) designed for multi-objective optimization have undergone no form of theoretical Stability analysis. This paper derives the sufficient and necessary conditions for order-1 and order-2 Stability of the recently proposed multi-guided PSO (MGPSO), which was designed specifically for multi-objective optimization. The paper utilizes a recently published theorem for performing Stability analysis on PSO variants, which requires minimal modeling assumptions. It is vital for PSO practitioners to know the actual criteria for Particle Stability of the given PSO variant being used, as it been shown that Particle Stability has a considerable impact on PSO’s performance. This paper empirically validates its theoretical findings by comparing the derived Stability criteria against those of an assumption free MGPSO algorithm. It was found that the derived criteria for order-1 and order-2 Stability are an accurate predictor of the unsimplified MGPSO’s Particle behavior.
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GECCO - Fitness-distance-ratio Particle swarm optimization: Stability analysis
Proceedings of the Genetic and Evolutionary Computation Conference, 2017Co-Authors: Christopher Wesley Cleghorn, Andries P. EngelbrechtAbstract:At present the fitness-distance-ratio Particle swarm optimizer (FDR-PSO) has undergone no form of theoretical Stability analysis. This paper theoretically derives the conditions necessary for order-1 and order-2 Stability under the well known stagnation assumption. Since it has been shown that Particle Stability has a meaningful impact on PSO's performance, it is important for PSO practitioners to know the actual criteria for Particle Stability. This paper validates its theoretical findings against an assumption free FDR-PSO algorithm. This empirical validation is necessary for a truly accurate representation of FDR-PSO's Stability criteria.
