25 research outputs found
358— Hybridization of Particle Swam Optimization and Pattern Search Algorithms With Application
No full textWe test three methods of hybridizing Particle Swarm Optimization (PSO) and Pattern Search (PS) to improve the global minima, speed, and robustness. All methods let PSO run first followed by PS. The first method lets PSO use a large number of particles for a limited number of iterations. The second method lets PSO run normally until tolerance is reached. The third method lets PSO run normally until the average particle distance from the global best location is within a threshold. Numerical results using non-differentiable test functions reveal that all three methods improve the global minima and robustness versus PSO, while the third method also improves speed versus PSO. The third hybrid method was also applied to a basin network optimization problem and outperformed PSO with filter method and Genetic Algorithm (GA) with implicit filtering
354— Observation of Acid Penetration of Nano-gold Doped Sol-gel System
No full textThe penetration of the acid into gold doped sol-gel material was measured. The acid penetration speed increased as the nano size increased up from 5 nm to 20 nm. Then there was almost no penetration at 60 nm. The nano dependent rate change was complex and needs to be investigated further. Also, recent new methodology to create the gel showed a significance stability and it took more than a few days to complete the penetration
Studying to Fail: The Relationship Between Stress and Memory and the Implications for Students
No full textThis paper reviews current literature on the topics of stress and memory and examines their relationship while emphasizing potential implications for students. The discussion begins with the underlying processes of the stress response and the impact that has on memory, with a focus on stress-induced retrieval impairment. Retrieval-induced forgetting is discussed with consideration of findings by Koessler et al. (2009) that stress has an inhibitory effect on the process. Variables that influence susceptibility to memory impairment, namely low extraversion (Law et al., 2012) and low arousal level of material (Buchanan et al., 2006; Goldfarb et al., 2019), are considered alongside suggestions for better study practices. Research is explored that demonstrates the effectiveness of retrieval practice as a defence against stress-induced retrieval impairment, and students are advised of the benefits that utilizing this practice may bring (Smith et al., 2018; Smith et al., 2016)
Incorporating Lindblad Decay Dynamics into Mixed Quantum-Classical Simulations
No full textWe derive the L-MFE method to incorporate Lindblad jump operator dynamics into the mean-field Ehrenfest (MFE) approach. We map the density matrix evolution of Lindblad dynamics onto pure state coefficients using trajectory averages. We use simple assumptions to construct the L-MFE method that satisfies this exact mapping. This establishes a method that exactly reproduces Lindblad decay dynamics using a wavefunction description, with deterministic changes of the magnitudes of the quantum expansion coefficients, while only adding on a stochastic phase. We further demonstrate that when including nuclei in the Ehrenfest dynamics, the L-MFE method gives semi-quantitatively accurate results, with the accuracy limited by the accuracy of the approximations present in the semiclassical MFE approach. This work provides a general framework to incorporate Lindblad dynamics into semiclassical or mixed quantum-classical simulations
A Model of Income Insurance and Social Norms
No full textA large literature on ex ante moral hazard in income insurance emphasizes that the individual can affect the probability of an income loss by choice of lifestyle and hence, the degree of risk-taking. The much smaller literature on moral hazard ex post mainly analyzes how a “moral hazard constraint” can make the individual abstain from fraud (“mimicking”). The present paper instead presents a model of moral hazard ex post without a moral hazard constraint; the individual's ability and willingness to work is represented by a continuous stochastic variable in the utility function, and the extent of moral hazard depends on the generosity of the insurance system. Our model is also well suited for analyzing social norms concerning work and benefit dependency.moral hazard, sick pay insurance, labor supply, asymmetric information
3D handheld laser scanner based approach for automatic identification and localization of EEG sensors
No full text3D handheld laser scanner based approach for automatic identification and localization of EEG sensors
No full textInternational audienceThis paper describes and assesses for the first time the use of a handheld 3D laser scanner for scalp EEG sensor localization and co-registration with magnetic resonance images. Study on five subjects showed that the scanner had an equivalent accuracy, a better repeatability, and was faster than the reference electromagnetic digitizer. According to electrical source imaging, somatosensory evoked potentials experiments validated its ability to give precise sensor localization. With our automatic labeling method, the data provided by the scanner could be directly introduced in the source localization studies
Implementation with evidence
No full textWe generalize the canonical problem of Nash implementation by allowing agents to voluntarily provide discriminatory signals, i.e. evidence. Evidence can either take the form of hard information or, more generally, have differential but non-prohibitive costs in different states. In such environments, social choice functions that are not Maskin-monotonic can be implemented. We formulate a more general property, evidence-monotonicity, and show that this is a necessary condition for implementation. Evidence-monotonicity is also sufficient for implementation in economic environments. In some settings, such as when agents have small preferences for honesty, any social choice function is evidence-monotonic. Additional characterizations are obtained for hard evidence. We discuss the relationship between the implementation problem where evidence provision is voluntary and a hypothetical problem where evidence can be chosen by the planner as part of an extended outcome space.Mechanism design, costly signaling, verifiable information, Nash implementation
Contagion through learning
No full textWe study learning in a large class of complete information normal form games. Players continually face new strategic situations and must form beliefs by extrapolation from similar past situations. We characterize the long-run outcomes of learning in terms of iterated dominance in a related incomplete information game with subjective priors. The use of extrapolations in learning may generate contagion of actions across games even if players learn only from games with payoffs very close to the current ones. Contagion may lead to unique long-run outcomes where multiplicity would occur if players learned through repeatedly playing the same game. The process of contagion through learning is formally related to contagion in global games, although the outcomes generally differ.Similarity, learning, contagion, case-based reasoning, global games
