Search results for " Navigation"
showing 10 items of 138 documents
Modelling forest decline using SMOS soil moisture and vegetation optical depth
2018
Global change is increasing the risk of forest decline worldwide, impacting carbon and water cycles. Hence, there is an urgent need for predicting forest decline occurrence. To that purpose, this study links forest decline events in Catalonia, detected by the DEBOSCAT forest monitoring program, with information from the Soil Moisture and Ocean Salinity (SMOS) satellite. Firstly, this study reviews the role of the SMOS soil moisture in a previous forest decline episode occurred in 2012, where the authors concluded that dry soils increased the probability of observing decline in broadleaved forests. Secondly, the present study detects that forest decline in 2012 and 2016 was linked to very dr…
Enhancing tracking performance in a smartphone-based navigation system for visually impaired people
2016
In this paper we show how to enhance the tracking performance of Arianna, a low-cost augmented reality system designed to meet the needs of people with problems of orientation, people with sight impairment and blind people. For augmented reality system we mean the design of: i) a set of paths and tags to be deployed in the environment, realized in various ways depending on the context (decorative elements easily identifiable, colorful stripes, QR code, RFID, etc.); ii) an instrument of mediation between the reality and the user (typically a smartphone) to access the information disseminated in the environment by means of a camera and provide a vibration feedback signal to the users for foll…
Clothoid-Based Three-Dimensional Curve for Attitude Planning
2019
Interest in flying robots, also known as unmanned aerial vehicles (UAVs), has grown during last years in both military and civil fields [1, 2]. The same happens to autonomous underwater vehicles (AUVs) [3]. These vehicles, UAVs and AUVs, offer a wide variety of possible applications and challenges, such as control, guidance or navigation [2, 3]. In this sense, heading and attitude control in UAVs is very important [4], particularly relevant in airplanes (fixed-wing flying vehicles), because they are strongly non-linear, coupled, and tend to be underactuated systems with non-holonomic constraints. Hence, designing a good attitude controller is a difficult task [5, 6, 7, 8, 9], where stabilit…
P-FCM: a proximity-based fuzzy clustering for user-centered web applications
2003
Abstract In last years, the Internet and the web have been evolved in an astonishing way. Standard web search services play an important role as useful tools for the Internet community even though they suffer from a certain difficulty. The web continues its growth, making the reliability of Internet-based information and retrieval systems more complex. Nevertheless there has been a substantial analysis of the gap between the expected information and the returned information, the work of web search engine is still very hard. There are different problems concerning web searching activity, one among these falls in the query phase. Each engine provide an interface which the user is forced to le…
Coupling News Sentiment with Web Browsing Data Improves Prediction of Intra-Day Price Dynamics
2015
The new digital revolution of big data is deeply changing our capability of understanding society and forecasting the outcome of many social and economic systems. Unfortunately, information can be very heterogeneous in the importance, relevance, and surprise it conveys, affecting severely the predictive power of semantic and statistical methods. Here we show that the aggregation of web users' behavior can be elicited to overcome this problem in a hard to predict complex system, namely the financial market. Specifically, our in-sample analysis shows that the combined use of sentiment analysis of news and browsing activity of users of Yahoo! Finance greatly helps forecasting intra-day and dai…
Adolescent and adult mice display differential sensitivity to the effects of bupropion on the acquisition of a water maze task.
2017
Abstract Background Adolescence is characterized by major neurobiological changes, and the effects of some psychoactive drugs seem to differ between adolescents and adults. Bupropion, an antidepressant that is also used to treat nicotine addiction, induces behavioral actions in both adolescent and adult rodents. However, the effects of this drug on spatial ability have not been compared in animals at different stages of their development. The present study was conducted to assess the effects of bupropion on spatial learning and memory in adolescent and adult mice. Methods Adolescent (post-natal day: PND35-36) and adult (PND >65) NMRI mice received bupropion (10, 20 and 40 mg/kg) or saline d…
Experienced Migratory Bats Integrate the Sun's Position at Dusk for Navigation at Night.
2019
Summary From bats to whales, millions of mammals migrate every year. However, their navigation capacity for accomplishing long-distance movements remains remarkably understudied and lags behind by five decades compared to other animals [ 1 , 2 ]—partly because, unlike for other taxa, such as birds and sea turtles, no small-scale orientation assay has so far been developed. Yet recently, bats became a model to investigate which cues mammals use for long-range navigation, and, surprisingly for nocturnal animals, sunset cues, and particularly polarized-light cues, appear to be crucial for calibration of the magnetic-compass system in non-migratory bats [ 3 , 4 , 5 ]. This does not appear to ho…
Impairment of Everyday Spatial Navigation Abilities in Mild Cognitive Impairment Is Weakly Associated with Reduced Grey Matter Volume in the Medial P…
2020
Alzheimer’s Disease Neuroimaging Initiative.
Reducing Peripheral Inflammation with Infliximab Reduces Neuroinflammation and Improves Cognition in Rats with Hepatic Encephalopathy
2016
Inflammation contributes to cognitive impairment in patients with hepatic encephalopathy (HE). However, the process by which peripheral inflammation results in cognitive impairment remains unclear. In animal models, neuroinflammation and altered neurotransmission mediate cognitive impairment. Taking into account these data, we hypothesized that in rats with HE: (1) peripheral inflammation is a main contributor to neuroinflammation; (2) neuroinflammation in hippocampus impairs spatial learning by altering AMPA and/or NMDA receptors membrane expression; (3) reducing peripheral inflammation with infliximab (anti-TNF-a) would improve spatial learning; (4) this would be associated with reduced n…
Algunas cuestiones de responsabilidad en la ley 14/2014, de 24 de julio, de navegación marítima
2015
La Ley española de Navegación Marítima ha reformado ampliamente el Derecho marítimo español, regulando prácticamente todos los aspectos de la navegación, tanto públicos como privados. El presente trabajo aborda algunos supuestos de responsabilidad que pueden plantearse en el ámbito de la navegación marítima y que el legislador español ha recogido en esta Ley The spanish Law of Maritime Navigation has reformed widely the spanish Maritime Law, regulatin practically all the aspects of the navigation, both public and privates. This paper approaches some suppositions of responsibility that can appear in the maritime navigation and that the spanish legislator has gathered in this Law.