Autonomous underwater vehicle control using reinforcement learning policy search methods

Autonomous underwater vehicles (AUV) represent a challenging control problem with complex, noisy, dynamics. Nowadays, not only the continuous scientific advances in underwater robotics but the increasing number of subsea missions and its complexity ask for an automatization of submarine processes. This paper proposes a high-level control system for solving the action selection problem of an autonomous robot. The system is characterized by the use of reinforcement learning direct policy search methods (RLDPS) for learning the internal state/action mapping of some behaviors. We demonstrate its feasibility with simulated experiments using the model of our underwater robot URIS in a target following task

Towards Direct Policy Search Reinforcement Learning for Robot Control

This paper proposes a high-level reinforcement learning (RL) control system for solving the action selection problem of an autonomous robot. Although the dominant approach, when using RL, has been to apply value function based algorithms, the system here detailed is characterized by the use of direct policy search methods. Rather than approximating a value function, these methodologies approximate a policy using an independent function approximator with its own parameters, trying to maximize the future expected reward. The policy based algorithm presented in this paper is used for learning the internal state/action mapping of a behavior. In this preliminary work, we demonstrate its feasibility with simulated experiments using the underwater robot GARBI in a target reaching task

Effects of memory load on visual search

Resumen tomado de la publicaci??n

TU Graz: Course: 707.000 Web Science and Web Technology: Lecture 7: Link Analysis and Search

What are ways of searching in graphs? In this class, we will discuss basics of link analysis, including Google's PageRank algorithm as an example. Readings: The PageRank Citation Ranking: Bringing Order to the Web, L. Page and S. Brin and R. Motwani and T. Winograd (1998) Stanford Tecnical Report

SPSS Topics Search - An animated guide

Need help on a given topic? Topics Search tab can help narrow down the search.

Library Guide: improving your search & Search Planner

A search planner to help structure a search (for journal articles in bibliographic databases). Also includes hints and tips on improving your search. This is a generic guide, useful for any subject.

eHandbook (TikiWiki) Handbook-Specific Search Module

Custom coded module for TikiWiki v4.2, allowing keyword search by Category. Auto-populates categories as new ones are created.

Hartley Library Search Planner

This 2-page planner will help students search databases more effectively using Boolean logic

Twitter en Colombia: ¿Cómo lo están usando las cadenas radiales para informar?

En Colombia los medios de comunicación, más específicamente las cadenas radiales nacionales más importantes, no se han quedado atrás y han optado por unirse desde hace unos años a twitter, incursionando sobre la marcha. Las cuentas de twitter de Bluradio, Caracol Radio y RCN Radio analizadas junto a las entrevistas con los encargados de las mismas y las emisiones de los programas de noticias escogidos, muestran que las redes sociales siguen siendo un desafío en la actualidad. Uno de esos desafíos es encontrar el verdadero objetivo de los medios en twitter y que este no sólo consista en la escucha activa en busca de las noticias de último momento. Para alcanzar una legitimidad comunicativa en la web 2.0 es necesario adaptarse a la cultura de la participación de las redes, de lo contrario se está condenado a obtener tan solo un nuevo canal de difusión de noticias.

Estudio preliminar para la adaptación del programa autoaplicable de elección vocacional self-directed search de John L. Holland.

Resumen tomado del autor. Resumen en inglés y castellano

O self-directed search (SDS) en Galicia

Se plantea la problem??tica de los j??venes de la toma de decisiones, tales como elegir una carrera, una profesi??n, argument??ndose que en ocasiones no est??n preparados para tomar dicha decisi??n. Por ello se realiza un an??lisis de la obra Self-Directed Search, SDS, Forma Regular, Edici??n 1994 del profesor Holland, el cual trata de explicar la conducta vocacional de los j??venes. Se describen los fundamentos te??ricos expuestos en esta obra, las diferentes tipolog??as personales, tambi??n se aportan algunas cr??ticas que ha recibido esta obra, se detallan sus m??todos, sus instrumentos, su m??todo y sus resultados.

Broadcast yourself : ¿oxímoron o confusión entre medios?

El artículo pertenece a una sección monográfica de la revista dedicada a nuevas formas de comunicación: cibermedios y medios móviles. - Resumen tomado parcialmente de la revista.

OpenSearch-geo: the simple standard for geographic web search engines

When publishing information on the web, one expects it to reach all the people that could be interested in. This is mainly achieved with general purpose indexing and search engines like Google which is the most used today. In the particular case of geographic information (GI) domain, exposing content to mainstream search engines is a complex task that needs specific actions. In many occasions it is convenient to provide a web site with a specially tailored search engine. Such is the case for on-line dictionaries (wikipedia, wordreference), stores (amazon, ebay), and generally all those holding thematic databases. Due to proliferation of these engines, A9.com proposed a standard interface called OpenSearch, used by modern web browsers to manage custom search engines. Geographic information can also benefit from the use of specific search engines. We can distinguish between two main approaches in GI retrieval information efforts: Classical OGC standardization on one hand (CSW, WFS filters), which are very complex for the mainstream user, and on the other hand the neogeographer’s approach, usually in the form of specific APIs lacking a common query interface and standard geographic formats. A draft ‘geo’ extension for OpenSearch has been proposed. It adds geographic filtering for queries and recommends a set of simple standard response geographic formats, such as KML, Atom and GeoRSS. This proposal enables standardization while keeping simplicity, thus covering a wide range of use cases, in both OGC and the neogeography paradigms. In this article we will analyze the OpenSearch geo extension in detail and its use cases, demonstrating its applicability to both the SDI and the geoweb. Open source implementations will be presented as well

Attention and selection behavior on ‘universal search’ result pages

The ISO norm line 9241 states some criteria for ergonomics of human system interaction. In markets with a huge variety of offers and little possibility of differentiation, providers can gain a decisive competitive advantage by user oriented interfaces. A precondition for this is that relevant information can be obtained for entrepreneurial decisions in this regard. To test how users of universal search result pages use those pages and pay attention to different elements, an eye tracking experiment with a mixed design has been developed. Twenty subjects were confronted with search engine result pages (SERPs) and were instructed to make a decision while conditions “national vs. international city” and “with vs. without miniaturized Google map” were used. Different parameters like fixation count, duration and time to first fixation were computed from the eye tracking raw data and supplemented by click rate data as well as data from questionnaires. Results of this pilot study revealed some remarkable facts like a vampire effect on miniaturized Google maps. Furthermore, Google maps did not shorten the process of decision making, Google ads were not fixated, visual attention on SERPs was influenced by position of the elements on the SERP and by the users’ familiarity with the search target. These results support the theory of Amount of Invested Mental Effort (AIME) and give providers empirical evidence to take users’ expectations into account. Furthermore, the results indicated that the task oriented goal mode of participants was a moderator for the attention spent on ads. Most important, SERPs with images attracted the viewers’ attention much longer than those without images. This unique selling proposition may lead to a distortion of competition on markets.