Hierarchical Policy Search via Return-Weighted Density Estimation

Learning an optimal policy from a multi-modal reward function is a challenging problem in reinforcement learning (RL). Hierarchical RL (HRL) tackles this problem by learning a hierarchical policy, where multiple option policies are in charge of different strategies corresponding to modes of a reward function and a gating policy selects the best option for a given context. Although HRL has been demonstrated to be promising, current state-of-the-art methods cannot still perform well in complex real-world problems due to the difficulty of identifying modes of the reward function. In this paper, we propose a novel method called hierarchical policy search via return-weighted density estimation (HPSDE), which can efficiently identify the modes through density estimation with return-weighted importance sampling. Our proposed method finds option policies corresponding to the modes of the return function and automatically determines the number and the location of option policies, which significantly reduces the burden of hyper-parameters tuning. Through experiments, we demonstrate that the proposed HPSDE successfully learns option policies corresponding to modes of the return function and that it can be successfully applied to a challenging motion planning problem of a redundant robotic manipulator.Comment: The 32nd AAAI Conference on Artificial Intelligence (AAAI 2018), 9 page

Frequency stability of a self-phase-locked degenerate continuous-wave optical parametric oscillator

The properties of a self-phase-locked by-2-divider optical parametric oscillator are presented. A locking range of up to 156 MHz is measured, and the divider's relative frequency stability is shown to be better than 6/spl times/10/sup -14/

Euripides: Master of the Discrepant Event

In Euripides’s Medea, a seemingly normative form of a traditional Greek tragedy is disturbed by a disruptive layer that shakes the audience to its core. Integral to the story of Medea is her revenge on Jason. One knows this, but Euripides adds a disruptive layer that increases the tragic tension of the story. This disruptive layer is the killing of innocent boys by their mother. And not only that, but the Mother being rewarded for this act. This paper shows how Euripides takes the traditional form of the Greek tragedy, adds disruptive layers, and makes the form his own

Implementación de una innovación docente en la asignatura Terapéutica Enfermera, Alimentación y Cuidados

Se presenta el primer ciclo de mejora llevado a cabo en la asignatura “Terapéutica Enfermera, Alimentación y Cuidados” de 2º curso del Grado en Enfermería, en la unidad docente Virgen del Rocío, con 51 estudiantes matriculados en un grupo grande, donde se planificó una secuencia de actividades que propiciaron la participación de estos en su proceso de aprendizaje. Se realizó un análisis previo y final de conocimientos, mediante un cuestionario ad hoc de 13 preguntas cerradas con cuatro opciones de respuesta, y en todas las preguntas hubo una mejora en los conocimientos

Evaluación de la conciencia fonológica en el incio lector

This study analyses the developnzent of assessment tools for the early identification of the possible risk of reading difficulties in preschool children. The assessment focuses on phonological awareness, a skill considered to be fundamental in beginning to read. Phonological awareness is evaluated through Word to Word Matching, Isolation of a Sound, and Invented Spelling tasks, using a sample of 214 kindergarten children. The results obtained show the existence of a significant linear connection between Phonological Awareness tasks and Reading Decoding, in particular Invented Spelling (r = .72; p = .0.1) were o f great importance for both research and reading-related educational practice.Se presenta una línea de investigación cuyo objetivo es establecer instrumentos de evaluación válidos para la identificación precoz de preescolares en posible riesgo de dificultades lectoras. La evaluación se ha centrado en unahabilidad considerada fundamental en el inicio y desarrollo lector: la conciencia fonológica, evaluada mediante las tareas Emparejar palabras, Aislar sonidos y Escritura inventada, en una muestra de 214 niños y niñas de Educación Infantil. Los resultados ohtenidos muestran la existencia de una relación lineal significativa entre las tareas de Conciencia fonológica y la Decodificación lectora, resaltando especialmente la Escritura inventada (r = .72; p = .OI), manifestándose ésta como una tarea con un gmn potencial tanto para la investigación como para la práctica educativa relacionada con la lectura

Julian of Norwich and her children today: Editions, translations and versions of her revelations

The viability of such concepts as "authorial intention," "the original text," "critical edition" and, above all, "scholarly editorial objectivity" is not what it was, and a study of the textual progeny of the revelations of Julian of Norwich--editions, versions, translations and selections--does little to rehabilitate them. Rather it tends to support the view that a history of reading is indeed a history of misreading or, more positively, that texts can have an organic life of their own that allows them to reproduce and evolve quite independently of their author. Julian's texts have had a more robustly continuous life than those of any other Middle English mystic. Their history--in manuscript and print, in editions more or less approximating Middle English and in translations more or less approaching Modern English--is virtually unbroken since the fifteenth century. But on this perilous journey, many and strange are the clutches into which she and her textual progeny have fallen