Detectability of f-mode Unstable Neutron Stars by the Schenberg Spherical Antenna

The Brazilian spherical antenna (Schenberg) is planned to detect high frequency gravitational waves (GWs) ranging from 3.0 kHz to 3.4 kHz. There is a host of astrophysical sources capable of being detected by the Brazilian antenna, namely: core collapse in supernova events; (proto)neutron stars undergoing hydrodynamical instability; f-mode unstable neutron stars, caused by quakes and oscillations; excitation of the first quadrupole normal mode of 4-9 solar mass black holes; coalescence of neutron stars and/or black holes; exotic sources such as bosonic or strange matter stars rotating at 1.6 kHz; and inspiralling of mini black hole binaries. We here address our study in particular to the neutron stars, which could well become f-mode unstable producing therefore GWs. We estimate, for this particular source of GWs, the event rates that in principle can be detected by Schenberg and by the Dutch Mini-Grail antenna.Comment: 7 pages, 3 figures; Classical and Quantum Gravity (in press

Chaotic and deterministic switching in a two-person game

We study robust long-term complex behaviour in the Rock-Scissors-Paper game with two players, played using reinforcement learning. The complex behaviour is connected to the existence of a heteroclinic network for the dynamics. This network is made of three heteroclinic cycles consisting of nine equilibria and the trajectories connecting them. We provide analytical proof both for the existence of chaotic switching near the heteroclinic network and for the relative asymptotic stability of at least one cycle in the network, leading to behaviour ranging from almost deterministic actions to chaotic-like dynamics. Our results are obtained by making use of the symmetry of the original problem, a new approach in the context of learning.learning process, dynamics, switching, chaos

A Uniform Approximation for the Coherent State Propagator using a Conjugate Application of the Bargmann Representation

We propose a conjugate application of the Bargmann representation of quantum mechanics. Applying the Maslov method to the semiclassical connection formula between the two representations, we derive a uniform semiclassical approximation for the coherent state propagator which is finite at phase space caustics.Comment: 4 pages, 1 figur

Rutherford scattering with radiation damping

We study the effect of radiation damping on the classical scattering of charged particles. Using a perturbation method based on the Runge-Lenz vector, we calculate radiative corrections to the Rutherford cross section, and the corresponding energy and angular momentum losses.Comment: Latex, 11 pages, 4 eps figure

Development of a Safety Performance Decision-Making Tool for Flight Training Organization

Title 14 of the Code of Federal Regulations (CFR) Part 141 flight training organizations are actively pursuing ways to increase operational safety by introducing advanced risk assessment and decision-making techniques. The purpose of the dissertation was to create and validate a safety performance decision-making tool to transform a reactive safety model into a predictive, safety performance decision-making tool, specific to large, collegiate Title 14 CFR Part 141 flight training organizations, to increase safety and aid in operational decision-making. The validated safety decision-making tool uses what-if scenarios to assess how changes to the controllable input variables impact the overall level of operational risk within an organization’s flight department. Utilizing SPIs determined to be most indicative of flight risk within large, collegiate flight training organizations, a predictive, safety performance decision-making tool was developed utilizing Monte Carlo simulation. In a high-risk system beset with uncertainty, applying Monte Carlo simulation addresses the need to accommodate uncontrollable inputs into the model in a manner that enables the model to produce meaningful output data. This research utilizes the validated equations drawn from the non-statistical model developed by Anderson, Aguiar, Truong, Friend, Williams, & Dickson (2020) for the mathematical inputs driving the computational nodes, including the SPIs, as the foundation to develop the safety performance decision-making tool. The probability distributions of the uncontrollable inputs were drawn from a sample of operational data from September 2017 to September 2019 from a large, collegiate 14 CFR Part 141 flight training organization in the southeastern United States. The study conducted simulation runs based on true operational ranges to simulate the operating conditions possible within large, collegiate CFR Part 141 flight training organizations with varying levels of controllable resources including personnel (Aviation Maintenance Technicians and Instructor Pilots) and expenditures (active flight students and available aircraft). The study compared the output from three different Verification Scenarios—each using a unique seed value to ensure a different sample of random numbers for the uncontrollable inputs. ANOVA testing indicated no significant differences appeared among the three different groups, indicating the results are statistically reliable. Four What-if Scenarios were conducted by manipulating the controllable inputs. Mean probability was the key output and represents the forecasted level of operational risk on a standardized 0-5 risk scale for the Flight Score, Maintenance Score, Damage and Related Impact, and an Overall Risk Score. Results indicate the lowest Overall Risk Score occurred when the level of personnel was high yet expenditures were moderate. Changes to the controllable inputs are reflected by variations to the outputs demonstrating the utility and potential for the safety performance decision-making tool. The outputs could be utilized by safety personnel and administrators to make more informed safety-related decisions without expending unnecessary resources. The model could be adapted for use in any CFR Part 141 flight training organization with data collection capabilities and an SMS by modifying the input value probability distributions to reflect the operating conditions of the selected 14 CFR Part 141 flight training organization