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

The close limit from a null point of view: the advanced solution

We present a characteristic algorithm for computing the perturbation of a Schwarzschild spacetime by means of solving the Teukolsky equation. We implement the algorithm as a characteristic evolution code and apply it to compute the advanced solution to a black hole collision in the close approximation. The code successfully tracks the initial burst and quasinormal decay of a black hole perturbation through 10 orders of magnitude and tracks the final power law decay through an additional 6 orders of magnitude. Determination of the advanced solution, in which ingoing radiation is absorbed by the black hole but no outgoing radiation is emitted, is the first stage of a two stage approach to determining the retarded solution, which provides the close approximation waveform with the physically appropriate boundary condition of no ingoing radiation.Comment: Revised version, published in Phys. Rev. D, 34 pages, 13 figures, RevTe

Remoção do pelo na adolescência

Introdução: Durante a puberdade devido à estimulação hormonal, ocorrem alterações do tipo e distribuição do pelo. Os pelos indesejados no corpo e na face, em ambos os sexos, podem ter um impacto psicológico negativo no adolescente. Existem disponíveis diversos métodos de remoção do pelo, mas a escolha do modo mais apropriado para cada indivíduo pode suscitar dúvidas. Objectivo: Rever os principais métodos de remoção do pelo e clarificar as suas indicações, vantagens e desvantagens. Desenvolvimento: Os métodos de remoção do pelo actualmente disponíveis são variados. A depilação com lâmina e com produtos químicos depilatórios são métodos temporários, em que existe a necessidade de repetição frequente do procedimento, uma vez que apenas existe a remoção do pelo junto à superfície cutânea. Os métodos epilatórios em que se procede à extração completa do pelo, incluem: epilação com cera, linha, pinça, máquinas epilatórias, laser, luz intensa pulsada, e eletrólise. Conclusão: A idade de inicio da remoção do pelo e a escolha do método deve ser individualizada e ter em consideração o tipo de pele e pelo, local, problemas dermatológicos e endocrinológicos, frequência de remoção, custo e preferências pessoais

The Impact Of Entry And Competition On Airline Departure Frequency

This paper examines how entry and competition impact departure frequency using data from 1990–2009 on a number of routes served by at least two airlines. The estimated frequency equation indicates that an additional airline at the route level results in a slight decrease in the number of departures despite a substantial increase in passenger traffic since the industry was liberalized in 1995. The results suggest that domestic airlines have shifted to relatively larger aircraft and operate them at higher load factors. The use of larger aircraft operated at higher load factors may indicate their inability to secure additional landing slots, suggesting that investments in air transport infrastructure have not kept pace with demand. Fewer departures indicate that the waiting time between flights has increased, reducing the probability of matching the passengers’ preferred departure times with scheduled flights. The longer waiting time between flights and more congestion inside the aircraft due to higher load factors suggest that the service quality of air transport has deteriorated in the post-regulation period

Factors Affecting Airline Profits: Evidence From The Philippines

This article examines the factors that affect the profits of four airlines in the Philippines. The estimated profit equation indicates that an additional passenger contributes PHP 1,989 to profits, while an additional seat reduces profits by PHP 1,312. The findings indicate that airlines have a strong incentive to fill a seat before departure, justifying the practice of heavy discounting to stimulate passenger traffic during periods of low demand. An additional route reduces profits by PHP 107.736 million, which may indicate that new routes have lower-than-expected passenger traffic. This may also suggest that most profitable routes are already served by at least one airline and entry into existing routes may not be profitable. The 1997 Asian financial crisis, the 2001 terror attacks in the United States, and the most recent global financial crisis, collectively result in PHP 1.391 billion reduction in profits, underscoring the vulnerability of the airline industry to unanticipated events

Large Merger Recoils and Spin Flips From Generic Black-Hole Binaries

We report the first results from evolutions of a generic black-hole binary, i.e. a binary containing unequal mass black holes with misaligned spins. Our configuration, which has a mass ratio of 2:1, consists of an initially non-spinning hole orbiting a larger, rapidly spinning hole (specific spin a/m = 0.885), with the spin direction oriented -45 degrees with respect to the orbital plane. We track the inspiral and merger for ~2 orbits and find that the remnant receives a substantial kick of 454 km/s, more than twice as large as the maximum kick from non-spinning binaries. The remnant spin direction is flipped by 103 degrees with respect to the initial spin direction of the larger hole. We performed a second run with anti-aligned spins, a/m = +-0.5 lying in the orbital plane that produces a kick of 1830 km/s off the orbital plane. This value scales to nearly 4000 km/s for maximally spinning holes. Such a large recoil velocity opens the possibility that a merged binary can be ejected even from the nucleus of a massive host galaxy.Comment: 4 pages. Accepted for publication in ApJ

Synthesis and characterization of novel thienyl-phthalazine based heterocyclic systems functionalized with (bi)thiophene moieties

The phthalazine moiety has a highly -deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good deficient aromatic character that makes it a good candidate to be incorporated as electron acceptor group, or even as spacer with auxiliary electron withdrawing abilities, into push-pull systems. Additionally, offers the possibility of protonation, hydrogen bond formation, and chelation through the nitrogen atoms. Phthalazine derivatives have applications as therapeutic agents, chemiluminescent materials, ligands in transition metal catalysis, and as optical materials. Some time ago, our research group developed a methodology for the preparation of phthalazine derivatives in three steps, affording halo-thienyl-phthalazine derivatives that play an important role in diazine chemistry since they offer great potential for further functionalization by nucleophilic displacement of the halogen, making numerous otherwise inaccessible diazines become available. In continuation of the work developed before by our research group, we report in this communication the synthesis and the evaluation of the optical properties of two novel thienyl-phthalazine derivatives, having in mind further functionalization to prepare push-pull heterocyclic systems for several optical and photovoltaic applications. These studies showed that the optical properties could be readily tuned by varying the π-conjugation path length through the introduction of a second thiophene unit.Thank are due to Fundação para a Ciência e Tecnologia (Portugal) and FEDER-COMPETE for financial support through Centro de Química (UID/QUI/00686/2013 and UID/ QUI/0686/2016), and a PhD grant to S. S. M. Fernandes (SFRH/BD/87786/2012). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005 with funds from POCI 2010 (FEDER) and FCT.info:eu-repo/semantics/publishedVersio