Physical animations using reinforcement learning

Trabajo de Fin de Grado en Desarrollo de Videojuegos, Facultad de Informática UCM, Departamento de Ingeniería del Software e Inteligencia Artificial, Curso 2020/2021, tanto el código fuente como todos los recursos que se han utilizado pueden encontrarse en el siguiente repositorio github.com/sergioabreu-g/physical-animations bajo la licencia de uso Apache 2.0.En la mayoría de videojuegos, las animaciones de los personajes están predefinidas, los artistas las crean durante el proceso de producción y así se quedan, cómo una serie de movimientos inmutables que se realizan al margen de la física del mundo en el que se encuentran. Las animaciones basadas en físicas vienen a solucionar este problema. Son igualmente creadas por artistas, pero dentro del juego las ejecutan personajes cuyos cuerpos están simulados mediante físicas realistas. Es decir, se simula cada parte del cuerpo cómo un objeto físico diferente, y se conectan entre ellas mediante articulaciones capaces de aplicar fuerzas, imitando el comportamiento de un cuerpo real. Aplicando las fuerzas adecuadas se puede hacer que estos personajes ejecuten las animaciones previamente creadas por los artistas. Esto consigue personajes que, no sólo pueden ver sus animaciones modificadas de manera natural ante perturbaciones externas, sino que también pueden interactuar con su entorno de forma realista. El movimiento natural que se consigue con esta técnica produce en el jugador una sensación de realismo e inmersión que sería imposible con animaciones tradicionales. Sin embargo, simular un personaje de esta forma presenta dos grandes problemas: el equilibrio y la estabilidad. Si simplemente se reprodujesen estas animaciones tal cual fueron creadas, el personaje no se mantendría de pie y perdería su trayectoria ante la más mínima perturbación. Esto se puede solucionar aplicando fuerzas artificiales que aseguren una postura concreta, pero así se pierde gran parte del realismo propio de esta técnica de animación. Una solución mejor es utilizar aprendizaje automático para que el personaje aprenda a estabilizarse aplicando fuerzas en sus articulaciones, intentando que al hacerlo su postura se parezca lo máximo posible a la de la animación. Esto es aún una frontera del desarrollo de videojuegos. En este trabajo exploramos el uso de aprendizaje por refuerzo para resolver la tarea del equilibrio en animaciones físicas. Para ello utilizamos Unity, uno de los motores de videojuegos más extendidos en la industria, con lo cual buscamos también comprobar cómo de accesibles son estas técnicas a día de hoy para los estudios de desarrollo.In most videogames, character animations are predefined, artists make them during the production process and so they stay, as an immutable series of movements that are played apart from the physics of the world they’re in. Physics-based animations try to solve that problem. They’re made by artists alike, but inside the game they’re played by characters whose bodies are being simulated with realistic physics. Namely, each part of the body is simulated as a different physical object, and then they’re connected by joints that can apply forces, mimicking the behavior of a real body. Applying the right forces one can make those characters play the animations previously made by the artists. And so you can achieve characters that not only can their animations be modified by external perturbations, but they can also interact with their environment in a more realistic manner. The movement attained with this technique provokes a sensation of realism and immersion in the player that would be impossible with traditional animation techniques. Nevertheless, physically simulating a character this way presents two big problems: balance and stability. If animations were just played as they were made, the character wouldn’t be able to stand or it would lose its trajectory when facing even the smallest perturbation. This can be fixed by applying artificial forces that ensure a specific pose, but at the cost of losing much of this technique’s realism. A better solution is to use machine learning so the character can learn to balance applying forces at its joints, trying to reach a pose as close as possible to the animation. This is still a frontier in game development. In this project, we explore the use of reinforcement learning to solve the task of balance in physics-based animations. For that we use Unity, one of the most renowned videogame engines, with which we also aim to test the accessibility of these techniques to game studios as of today.Depto. de Ingeniería de Software e Inteligencia Artificial (ISIA)Fac. de InformáticaTRUEunpu

Quality of life related to health in children and adolescents with cancer treated at Oncohematology services Havana, 2011-2013

Introduction: The impact and psychological repercussion of cancer in childhood justify the importance of the researches on quality of life related to patients’ health. Objective: Describe the researches with socio-demographic and clinical variables on onco-pediatric patients who are under oncohematological services in Havana from 2011 to 2013. Material and Methods:  A descriptive research with 150 children that fulfill the inclusion criteria. A system of life quality evaluation for children who suffer from cancer was applied; this system of evaluation was developed in Cuba. Punctual and at interval appraisals were done to the 95% of the global arithmetic average and by dimension through socio-demographic and clinical variables. Different test were used; t student for independent samples, the ANOVA of one way and the Scheffe. Results: The global average of the quality of life related to health was 3, 49. The worst evolutions were on the dimension of symptoms associated to treatment (5, 88) and for preoccupations. There were significant differences in different dimensions for socio-demographic and clinical variables. Conclusions: The patients showed high and average levels of quality of life related to health. The dimensions: symptoms associated to treatment, preoccupations, emotional symptoms, validity and primary symptoms were the worst evaluated dimensions. Academic level, type of treatment, and time of evolution differentiate patients with a tendency to have a better or worse global quality of life related to health. Key words: oncohematology, quality of life related with health, pediatrics, cancer, pediatric oncology.</p

Les Guanches dans les montagnes de Tenerife : l’étude interdisciplinaire d’une population de substrat amazighe aux îles canaries

Cet article présente les principaux résultats des projets de recherche multidisciplinaires, menés ces dernières années dans le paysage volcanique de haute montagne de Tenerife (dans le Parc National de Las Cañadas del Teide, dans les Îles Canaries). Cet article a pour objectifs d’étudier l’évolution du peuplement autochtone des Guanches, dont le substrat culturel se rattacheaux populations amazighes de l’Afrique du nord, de proposer les outils basiques, requis pour aborder des modèles d’occupation similaires, et d’élaborer des stratégies de dissémination viables. Le modèle, décrit dans cet article est un modèle d’occupation, de production et de communication complexe, appréhendé dans son ensemble, il s’agit notamment celui mené par les aborigènes dans les montagnes de Tenerife

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

Enabling planetary science across light-years. Ariel Definition Study Report

Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution

The wide-field, multiplexed, spectroscopic facility WEAVE: Survey design, overview, and simulated implementation

WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree field-of-view prime-focus corrector system, a nearly 1000-multiplex fibre positioner, 20 individually deployable 'mini' integral field units (IFUs), and a single large IFU. These fibre systems feed a dual-beam spectrograph covering the wavelength range 366$-$959\,nm at $R\sim5000$, or two shorter ranges at $R\sim20\,000$. After summarising the design and implementation of WEAVE and its data systems, we present the organisation, science drivers and design of a five- to seven-year programme of eight individual surveys to: (i) study our Galaxy's origins by completing Gaia's phase-space information, providing metallicities to its limiting magnitude for $\sim$3 million stars and detailed abundances for $\sim1.5$ million brighter field and open-cluster stars; (ii) survey $\sim0.4$ million Galactic-plane OBA stars, young stellar objects and nearby gas to understand the evolution of young stars and their environments; (iii) perform an extensive spectral survey of white dwarfs; (iv) survey $\sim400$ neutral-hydrogen-selected galaxies with the IFUs; (v) study properties and kinematics of stellar populations and ionised gas in $z<0.5$ cluster galaxies; (vi) survey stellar populations and kinematics in $\sim25\,000$ field galaxies at $0.3\lesssim z \lesssim 0.7$; (vii) study the cosmic evolution of accretion and star formation using $>1$ million spectra of LOFAR-selected radio sources; (viii) trace structures using intergalactic/circumgalactic gas at $z>2$. Finally, we describe the WEAVE Operational Rehearsals using the WEAVE Simulator.Comment: 41 pages, 27 figures, accepted for publication by MNRA