Online Robust 3D Mapping Using Structure from Motion Cues

This paper presents a complete solution for creating accurate 3D textured models from monocular video sequences. The methods are developed within the framework of sequential structure from motion, where a 3D model of the environment is maintained and updated as new visual information becomes available. The camera position is recovered by directly associating the 3D scene model with local image observations. Compared to standard structure from motion techniques, this approach decreases the error accumulation while increasing the robustness to scene occlusions and feature association failures. The obtained 3D information is used to generate high quality, composite visual maps of the scene (mosaics). The visual maps are used to create texture-mapped, realistic views of the scene

The Role of the online learner: onsite students becoming online learners

As universities are offering tuition through online learning environments, “onsite students” in higher education are increasingly becoming “online learners”. Since the medium for learning (and teaching) online is a digital environment, and at a distance, the role taken by students and teaching staff is different to the one these are used to in onsite, traditional settings. Therefore the Role of the Online Learner, presented in this paper, is key to onsite students who are to become online learners. This role consists of five competences: Operational, Cognitive, Collaborative, Self-directing, Course-specific. These five competences integrate the various skills, strategies, attitudes and awareness that make up the role of online learner, which learners use to perform efficiently online. They also make up the basis of a tutorial for would-be online learners, going over the Role of the Online Learner by means of concepts, examples and reflective activities. This tutorial, available to students in the author’s website, is also helpful to teaching and counselling staff in guiding their students to become online learners

OpenLayers

En este ultimo año y medio el mundo del Web Mapping ha visto nacer y crecer una comunidad muy activa alrededor de OpenLayers, una librería en Javascript para la publicación de mapas en el web. En este artículo se muestran las rutinas y herramientas para la creación de una aplicación de Web Mapping con OpenLayers. OpenLayers ofrece muchas herramientas con las que añadir al mapa, capas raster desde servicios WMS o desde servicios propietarios como los de Google Maps. Ademas, cuenta con una nueva librería de dibujo vectorial con lo que veremos como relacionarse con el editing online. En conclusión, vamos a evaluar el futuro de OpenLayers con las nuevas funciones y soporte a formatos con los que se esta trabajando

Ka-Map: an interactive web-mapping application

ka-Map ("ka" as in ka-boom!) is an open source project that is aimed at providing a javascript API for developing highly interactive web-mapping interfaces using features available in modern web browsers. ka-Map currently has a number of interesting features. It sports the usual array of user interface elements such as: interactive, continuous panning without reloading the page; keyboard navigation options (zooming, panning); zooming to pre-set scales; interactive scalebar, legend and keymap support; optional layer control on client side; server side tile caching

Interoperabilidad del servicio de nomenclator y catálogo online del Instituto de Cartografía de Andalucía

El servicio WFS-G de Nomenclátor del Instituto de Cartografía de Andalucía (ICA) basa sus servicios en una base de datos que sigue el estándar del Modelo de Nomenclátor de España y que actualmente contiene unos 149.500 topónimos e identificadores geográficos clasificados temáticamente en áreas administrativas, entidades de población, hidrografía, orografía, patrimonio, infraestructuras, actividades industriales, extractivas, servicios y equipamientos. Este servicio OGC basado en el software libre Deegree 2.2. trata de dar servicio a otros proyectos del ICA como la IDEAndalucia, el catálogo de productos on-line LINE@ y en un futuro al buscador de cartografía histórica; por otro lado dispone de un visor propio de búsqueda de nombres geográficos con utilidades de descarga, rectificación y localización de topónimos cercanos

Semi-online neural-Q_leaming for real-time robot learning

Reinforcement learning (RL) is a very suitable technique for robot learning, as it can learn in unknown environments and in real-time computation. The main difficulties in adapting classic RL algorithms to robotic systems are the generalization problem and the correct observation of the Markovian state. This paper attempts to solve the generalization problem by proposing the semi-online neural-Q_learning algorithm (SONQL). The algorithm uses the classic Q_learning technique with two modifications. First, a neural network (NN) approximates the Q_function allowing the use of continuous states and actions. Second, a database of the most representative learning samples accelerates and stabilizes the convergence. The term semi-online is referred to the fact that the algorithm uses the current but also past learning samples. However, the algorithm is able to learn in real-time while the robot is interacting with the environment. The paper shows simulated results with the "mountain-car" benchmark and, also, real results with an underwater robot in a target following behavior

A behavior-based scheme using reinforcement learning for autonomous underwater vehicles

This paper presents a hybrid behavior-based scheme using reinforcement learning for high-level control of autonomous underwater vehicles (AUVs). Two main features of the presented approach are hybrid behavior coordination and semi on-line neural-Q_learning (SONQL). Hybrid behavior coordination takes advantages of robustness and modularity in the competitive approach as well as efficient trajectories in the cooperative approach. SONQL, a new continuous approach of the Q_learning algorithm with a multilayer neural network is used to learn behavior state/action mapping online. Experimental results show the feasibility of the presented approach for AUVs

QoS online routing and MPLS multilevel protection: a survey

A survey of MPLS protection methods and their utilization in combination with online routing methods is presented in this article. Usually, fault management methods pre-establish backup paths to recover traffic after a failure. In addition, MPLS allows the creation of different backup types, and hence MPLS is a suitable method to support traffic-engineered networks. In this article, an introduction of several label switch path backup types and their pros and cons are pointed out. The creation of an LSP involves a routing phase, which should include QoS aspects. In a similar way, to achieve a reliable network the LSP backups must also be routed by a QoS routing method. When LSP creation requests arrive one by one (a dynamic network scenario), online routing methods are applied. The relationship between MPLS fault management and QoS online routing methods is unavoidable, in particular during the creation of LSP backups. Both aspects are discussed in this article. Several ideas on how these actual technologies could be applied together are presented and compared

Mapping sub-flows to p2mp LSPs

In previous work we proposed a multi-objective traffic engineering scheme (MHDB-S model) using different distribution trees to multicast several flows. In this paper, we propose a heuristic algorithm to create multiple point-to-multipoint (p2mp) LSPs based on the optimum sub-flow values obtained with our MHDB-S model. Moreover, a general problem for supporting multicasting in MPLS networks is the lack of labels. To reduce the number of labels used, a label space reduction algorithm solution is also considered

The mapping of the local contributions of Fermi and Coulomb correlation into intracule and extracule density distributions

The contributions of the correlated and uncorrelated components of the electron-pair density to atomic and molecular intracule I(r) and extracule E(R) densities and its Laplacian functions ∇2I(r) and ∇2E(R) are analyzed at the Hartree-Fock (HF) and configuration interaction (CI) levels of theory. The topologies of the uncorrelated components of these functions can be rationalized in terms of the corresponding one-electron densities. In contrast, by analyzing the correlated components of I(r) and E(R), namely, IC(r) and EC(R), the effect of electron Fermi and Coulomb correlation can be assessed at the HF and CI levels of theory. Moreover, the contribution of Coulomb correlation can be isolated by means of difference maps between IC(r) and EC(R) distributions calculated at the two levels of theory. As application examples, the He, Ne, and Ar atomic series, the C2-2, N2, O2+2 molecular series, and the C2H4 molecule have been investigated. For these atoms and molecules, it is found that Fermi correlation accounts for the main characteristics of IC(r) and EC(R), with Coulomb correlation increasing slightly the locality of these functions at the CI level of theory. Furthermore, IC(r), EC(R), and the associated Laplacian functions, reveal the short-ranged nature and high isotropy of Fermi and Coulomb correlation in atoms and molecules

Casos de aplicaciones empresariales de Web Mapping y SIG Libre

La incorporación Software Libre para Geomática (FOSS4G), para la explotación de Información Geoespacial en Sistemas de Información (SI) empresariales es una tendencia inexorable. Aunque estas tecnologías se están difundiendo con rapidez en entornos de empresas especializadas, Universidades, Administraciones Públicas y Centros Tecnológicos, todavía es algo incipiente en grandes empresas, especialmente en aquellas no directamente relacionadas con las tecnologías de los SIG. El objetivo de esta presentación será mostrar cómo se está consiguiendo introducir el software de SIG libre en el mundo empresarial, con tres casos de éxito. El primero es un desarrollo tradicional para una compañía tipo ‘utility’ donde el cliente define una funcionalidad y contrata su desarrollo. El segundo es un modelo de contratación de servicios. La tercera es una aplicación para la administración pública. En los tres casos, el uso de software libre ha permitido ofrecer soluciones exitosas para los requerimientos de los clientes (tanto funcionales como de rendimiento), y óptimas en coste

De la Presencialitat i de l'online, on acaba una i comença l´altra? Propostes per a plantejar-les, disfrutar-les i valorar-les'

Hi ha dos tipus d'interrogants que ens plantegem en aquesta presentació: En primer lloc exposem un seguit de realitats que afecten directament al disseny de la nostra assignatura: els professors assumim habilitats apreses en tècniques de treball dels nostres estudiants: treball en equip, presentacions, debats.... Els uns i els altres entenem el mateix, del què i el com s'ha de treballar? Ho comprovarem. Alhora, ens preguntarem si els estudiants assumim habilitats tecnològiques del professorat? Moodle, wikis, Twitter, xats..... tots entenem el mateix i els fem servir de la mateixa manera? Fixem-nos en les dues perspectives, la del professor i la de l'estudiant, tant referent a dinamiques com a recursos, i ens adonarem que cal tenir en compte tant la una com l'altra. Aquestes reflexions afecten al plantejament de l'assignatura i ens deixen clar que hi ha molta feina a fer per trobar les respostes (conèixer als estudiants que tenim a les aules, explicar convenientment el que esperem dels estudiants, com plantegem l'assignatura i com l'avaluarem... ) No ens referim exclusivament a tenir un pla docent detallat a la maxima expresió, sinó que ens referim a reconèixer el com, el quan i el que expliquem als nostres estudiants, de manera que les regles del joc quedin enteses de la mateixa manera per una part i per l'altra. A partir d'aquí, i com a segon interrogant, ens plantejarem l'estructura que combina la part presencial i la part no presencial de l'assignatura: Quines són les activitats de les que puc treure més rendiment en la part presencial de l'assignatura i quines en la part no presencial? Quant temps i com calcular-lo, cal invertir en les activitats, tant per part dels estudiants com per part del professorat? Com podem avaluar una activitat que ha estat realitzada en part presencial i en part no presencial

El Uso de fuentes primarias archivísticas online para la formación universitaria en ciencias sociales: una propuesta de trabajo interdisciplinar

El trabajo formula propuestas para la utilización de recursos didácticos basados en fuentes primarias en la docencia universitaria de ciencias sociales. Nos centramos en las fuentes disponibles en el Archivo Histórico Eclesiástico de Bizkaia, que en los últimos años ha realizado un esfuerzo notable por dar accesibilidad online a sus fondos. La comunicación explora las potencialidades que ofrece este tipo de fuentes, al permitir a los estudiantes universitarios entrar en contacto con fuentes originales, criticarlas, efectuar un tratamiento correcto de la información y, en definitiva, aproximarse al método científico. Todo ello diseñado desde una perspectiva centrada en el estudiante

Efficient 3D scene modeling and mosaicing

El modelat d'escenes és clau en un gran ventall d'aplicacions que van des de la generació mapes fins a la realitat augmentada. Aquesta tesis presenta una solució completa per a la creació de models 3D amb textura. En primer lloc es presenta un mètode de Structure from Motion seqüencial, a on el model 3D de l'entorn s'actualitza a mesura que s'adquireix nova informació visual. La proposta és més precisa i robusta que l'estat de l'art. També s'ha desenvolupat un mètode online, basat en visual bag-of-words, per a la detecció eficient de llaços. Essent una tècnica completament seqüencial i automàtica, permet la reducció de deriva, millorant la navegació i construcció de mapes. Per tal de construir mapes en àrees extenses, es proposa un algorisme de simplificació de models 3D, orientat a aplicacions online. L'eficiència de les propostes s'ha comparat amb altres mètodes utilitzant diversos conjunts de dades submarines i terrestres.

Efficient topology estimation for large scale optical mapping

Large scale image mosaicing methods are in great demand among scientists who study different aspects of the seabed, and have been fostered by impressive advances in the capabilities of underwater robots in gathering optical data from the seafloor. Cost and weight constraints mean that lowcost Remotely operated vehicles (ROVs) usually have a very limited number of sensors. When a low-cost robot carries out a seafloor survey using a down-looking camera, it usually follows a predetermined trajectory that provides several non time-consecutive overlapping image pairs. Finding these pairs (a process known as topology estimation) is indispensable to obtaining globally consistent mosaics and accurate trajectory estimates, which are necessary for a global view of the surveyed area, especially when optical sensors are the only data source. This thesis presents a set of consistent methods aimed at creating large area image mosaics from optical data obtained during surveys with low-cost underwater vehicles. First, a global alignment method developed within a Feature-based image mosaicing (FIM) framework, where nonlinear minimisation is substituted by two linear steps, is discussed. Then, a simple four-point mosaic rectifying method is proposed to reduce distortions that might occur due to lens distortions, error accumulation and the difficulties of optical imaging in an underwater medium. The topology estimation problem is addressed by means of an augmented state and extended Kalman filter combined framework, aimed at minimising the total number of matching attempts and simultaneously obtaining the best possible trajectory. Potential image pairs are predicted by taking into account the uncertainty in the trajectory. The contribution of matching an image pair is investigated using information theory principles. Lastly, a different solution to the topology estimation problem is proposed in a bundle adjustment framework. Innovative aspects include the use of fast image similarity criterion combined with a Minimum spanning tree (MST) solution, to obtain a tentative topology. This topology is improved by attempting image matching with the pairs for which there is the most overlap evidence. Unlike previous approaches for large-area mosaicing, our framework is able to deal naturally with cases where time-consecutive images cannot be matched successfully, such as completely unordered sets. Finally, the efficiency of the proposed methods is discussed and a comparison made with other state-of-the-art approaches, using a series of challenging datasets in underwater scenarios