Visual SLAM for 3D large-scale seabed acquisition employing underwater vehicles

This paper presents a novel technique to align partial 3D reconstructions of the seabed acquired by a stereo camera mounted on an autonomous underwater vehicle. Vehicle localization and seabed mapping is performed simultaneously by means of an Extended Kalman Filter. Passive landmarks are detected on the images and characterized considering 2D and 3D features. Landmarks are re-observed while the robot is navigating and data association becomes easier but robust. Once the survey is completed, vehicle trajectory is smoothed by a Rauch-Tung-Striebel filter obtaining an even better alignment of the 3D views and yet a large-scale acquisition of the seabed

Visual SLAM for underwater vehicles using video velocity log and natural landmarks

A visual SLAM system has been implemented and optimised for real-time deployment on an AUV equipped with calibrated stereo cameras. The system incorporates a novel approach to landmark description in which landmarks are local sub maps that consist of a cloud of 3D points and their associated SIFT/SURF descriptors. Landmarks are also sparsely distributed which simplifies and accelerates data association and map updates. In addition to landmark-based localisation the system utilises visual odometry to estimate the pose of the vehicle in 6 degrees of freedom by identifying temporal matches between consecutive local sub maps and computing the motion. Both the extended Kalman filter and unscented Kalman filter have been considered for filtering the observations. The output of the filter is also smoothed using the Rauch-Tung-Striebel (RTS) method to obtain a better alignment of the sequence of local sub maps and to deliver a large-scale 3D acquisition of the surveyed area. Synthetic experiments have been performed using a simulation environment in which ray tracing is used to generate synthetic images for the stereo system

Disseny d'una eina visual per a la configuració d'Iptables

Es dissenya una eina per configurar Iptables en una distribució de xarxa. L'eina permet a través d'una interfície gràfica definir una tipologia de xarxa i generar automàticament els scripts de configuració.

Individual differences in control of language interference in late bilinguals are mainly related to general executive abilities

Background: Recent research based on comparisons between bilinguals and monolinguals postulates that bilingualism enhances cognitive control functions, because the parallel activation of languages necessitates control of interference. In a novel approach we investigated two groups of bilinguals, distinguished by their susceptibility to cross-language interference, asking whether bilinguals with strong language control abilities ('non-switchers") have an advantage in executive functions (inhibition of irrelevant information, problem solving, planning efficiency, generative fluency and self-monitoring) compared to those bilinguals showing weaker language control abilities ('switchers"). Methods: 29 late bilinguals (21 women) were evaluated using various cognitive control neuropsychological tests [e.g., Tower of Hanoi, Ruff Figural Fluency Task, Divided Attention, Go/noGo] tapping executive functions as well as four subtests of the Wechsler Adult Intelligence Scale. The analysis involved t-tests (two independent samples). Non-switchers (n = 16) were distinguished from switchers (n = 13) by their performance observed in a bilingual picture-naming task. Results: The non-switcher group demonstrated a better performance on the Tower of Hanoi and Ruff Figural Fluency task, faster reaction time in a Go/noGo and Divided Attention task, and produced significantly fewer errors in the Tower of Hanoi, Go/noGo, and Divided Attention tasks when compared to the switchers. Non-switchers performed significantly better on two verbal subtests of the Wechsler Adult Intelligence Scale (Information and Similarity), but not on the Performance subtests (Picture Completion, Block Design). Conclusions: The present results suggest that bilinguals with stronger language control have indeed a cognitive advantage in the administered tests involving executive functions, in particular inhibition, self-monitoring, problem solving, and generative fluency, and in two of the intelligence tests. What remains unclear is the direction of the relationship between executive functions and language control abilities.

Unsupervised visual object categorization

The number of digital images has been increasing exponentially in the last few years. People have problems managing their image collections and finding a specific image. An automatic image categorization system could help them to manage images and find specific images. In this thesis, an unsupervised visual object categorization system was implemented to categorize a set of unknown images. The system is unsupervised, and hence, it does not need known images to train the system which needs to be manually obtained. Therefore, the number of possible categories and images can be huge. The system implemented in the thesis extracts local features from the images. These local features are used to build a codebook. The local features and the codebook are then used to generate a feature vector for an image. Images are categorized based on the feature vectors. The system is able to categorize any given set of images based on the visual appearance of the images. Images that have similar image regions are grouped together in the same category. Thus, for example, images which contain cars are assigned to the same cluster. The unsupervised visual object categorization system can be used in many situations, e.g., in an Internet search engine. The system can categorize images for a user, and the user can then easily find a specific type of image.

Implementação da comunicação visual e procedimentos de conservação da obra Chemical Abstracts - Uma experiência da divisão de Biblioteca e documentação do conjunto das Químicas/USP

This paper proposes a model for visual communication, conservation, and maintenance of the collection "Chemical Abstracts". It describes the various steps for its implementation and makes considerations about the whole reference work.

Uma demonstração simples e visual do efeito do aquecimento com microondas em reações de poliadição

Polyaddition of commercial monomers is easily performed on a domestic microwave oven. The rate of polymerization depends on the structure of the monomer, power and time of irradiation. This methodology can easily be used to demonstrate the acceleration of organic reactions promoted by microwaves.

Plug-in de procesado visual (OpenCV) en OpenDomo OS

Este proyecto consiste en el diseño y desarrollo de un plug-in que permita usar el sistema de procesado de imagen OpenCV desde el sistema operativo OpenDomo OS.

Control doméstico visual desde Android : VisualDomo

VisualDomo tiene como objetivo la creación de una aplicación multiplataforma para dispositivos móviles que permita controlar de manera visual los dispositivos ODControl de la empresa OpenDomo Services SL. El proyecto está desarrollado utilizando HTML, CSS y JavaScript con el soporte de Cordova.

Control domèstic visual per a Android

El projecte desenvolupa una aplicació visual per a dispositius mòbils basada en PhoneGap - Cordova (HTML + CSS + JavaScript) per al control del dispositiu ODControl de l'empresa OpenDomo Services.

PROPUESTA DE UN AMBIENTE E-LEARNING PARA EL FORTALECIMIENTO DE LAS HABILIDADES DE ALFABETIZACIÓN VISUAL E INFORMACIONAL: CASO LICENCIATURA EN ELECTRÓNICA - UPN.

El proyecto "Propuesta de un ambiente e-learning para el fortalecimiento de las habilidades de alfabetización visual e informacional: caso Licenciatura en Electrónica - UPN" fortalece la investigación alrededor de ambientes e-learning de la Universitat Oberta de Catalunya (UOC). Con la investigación se buscó determinar las estrategias organizativas, pedagógicas y tecnológicas a implementar en el diseño y desarrollo de un entorno e-learning que promueva las habilidades de alfabetización visual e informacional en estudiantes de primer semestre de la Licenciatura en Electrónica de la Universidad Pedagógica Nacional de Colombia. La investigación realizada fue de tipo cualitativo a través de un estudio de caso.

Retrats d'acollida : Una aproximació des de l'etnografia visual a les cuidadores i cuidadors de la Fundació Pere Mitjans

Acostament etnogràfic visual a un grup de cuidadors/es de la Fundació Pere Mitjans. Descobriment de l'empatia d'un col·lectiu divers de cuidadors/es amb el grup d'usuaris amb l'etiqueta de diferents, per la seva discapacitat o diversitat funcional.

Does visual impairment in a child or an adolescent affect their parents' quality of life? : A literature review

The purpose of this research was to determine whether the existing research shows that having a child with a visual impairment affects their parents' quality of life and, if it is thecase, in what way it does.

Effects of neurotrophins on synaptic protein expression in the visual cortex of dark reared rats.

Total lack of visual experience [dark rearing (DR)] is known to prolong the critical period and delay development of sensory functions in mammalian visual cortex. Recent results show that neurotrophins (NTs) counteract the effects of DR on functional properties of visual cortical cells and exert a strong control on critical period duration. NTs are known to modulate the development and synaptic efficacy of neurotransmitter systems that are affected by DR. However, it is still unknown whether the actions of NTs in dark-reared animals involve interaction with neurotransmitter systems. We have studied the effects of DR on the expression of key molecules in the glutamatergic and GABAergic systems in control and NT-treated animals. We have found that DR reduced the expression of the NMDA receptor 2A subunit and its associated protein PSD-95 (postsynaptic density-95), of GRIP (AMPA glutamate receptor interacting protein), and of the biosynthetic enzyme GAD (glutamic acid decarboxylase). Returning dark-reared animals to light for 2 hr restored normal expression of the above-mentioned proteins almost completely. NT treatment specifically counteracts DR effects; NGF acts primarily on the NMDA system, whereas BDNF acts primarily on the GABAergic system. Finally, the action of NT4 seems to involve both excitatory and inhibitory systems. These data demonstrate that different NTs counteract DR effects by modulating the expression of key molecules of the excitatory and inhibitory neurotransmitter systems

Efficient image mosaicing for multi-robot visual underwater mapping

Robotic platforms have advanced greatly in terms of their remote sensing capabilities, including obtaining optical information using cameras. Alongside these advances, visual mapping has become a very active research area, which facilitates the mapping of areas inaccessible to humans. This requires the efficient processing of data to increase the final mosaic quality and computational efficiency. In this paper, we propose an efficient image mosaicing algorithm for large area visual mapping in underwater environments using multiple underwater robots. Our method identifies overlapping image pairs in the trajectories carried out by the different robots during the topology estimation process, being this a cornerstone for efficiently mapping large areas of the seafloor. We present comparative results based on challenging real underwater datasets, which simulated multi-robot mapping