4,125 research outputs found

    Gas Source Localization Strategies for Teleoperated Mobile Robots. An Experimental Analysis

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    Gas source localization (GSL) is one of the most important and direct applications of a gas sensitive mobile robot, and consists in searching for one or multiple volatile emission sources with a mobile robot that has improved sensing capabilities (i.e. olfaction, wind flow, etc.). This work adresses GSL by employing a teleoperated mobile robot, and focuses on which search strategy is the most suitable for this teleoperated approach. Four different search strategies, namely chemotaxis, anemotaxis, gas-mapping, and visual-aided search, are analyzed and evaluated according to a set of proposed indicators (e.g. accuracy, efficiency, success rate, etc.) to determine the most suitable one for a human-teleoperated mobile robot. Experimental validation is carried out employing a large dataset composed of over 150 trials where volunteer operators had to locate a gas-leak in a virtual environment under various and realistic environmental conditions (i.e. different wind flow patterns and gas source locations). We report different findings, from which we highlight that, against intuition, visual-aided search is not always the best strategy, but depends on the environmental conditions and the operator’s ability to understand how gas distributes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Project based learning on industrial informatics: applying IoT to urban garden

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    Copyright (c) 2018 IEEEThe fast evolution of technologies forces teachers to trade content off for self-learning. PBL is one of the best ways to promote self-learning and simultaneously boost motivation. In this paper, we present our experience introducing project-based learning in the last year subject. New Internet of Things (IoT) topic allows us to carry out complete projects, integrating different technologies and tools. Moreover, the selection of open-source and standard free technologies makes easy and cheap the access to hardware and software platforms used. We carefully have picked communication, data management, and programming tools that we think would be attractive to our students. They can start making fast prototyping with little initial skills and, at the same time, these are serious and popular tools widely used in the industry. In this paper, we report on the design of a project-based learning for our course and the impact this has on the student satisfaction and motivation. Surveys taught us that tuning the courses towards developing real projects on the field, has a large impact on acceptance, learning objectives achievements and motivation towards the course content.”I Plan Propio Integral de Docencia de la Universidad de Málaga” y Proyecto de Innovación Educativa PIE17/085, de la Universidad de Málaga. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Integrating Olfaction in a Robotic Telepresence Loop

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    In this work we propose enhancing a typical robotic telepresence architecture by considering olfactory and wind flow information in addition to the common audio and video channels. The objective is to expand the range of applications where robotics telepresence can be applied, including those related to the detection of volatile chemical substances (e.g. land-mine detection, explosive deactivation, operations in noxious environments, etc.). Concretely, we analyze how the sense of smell can be integrated in the telepresence loop, covering the digitization of the gases and wind flow present in the remote environment, the transmission through the communication network, and their display at the user location. Experiments under different environmental conditions are presented to validate the proposed telepresence system when localizing a gas emission leak at the remote environment.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Stakeholder, Transparency and Capital Structure

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    Firms that are more highly levered are forced to raise capital more often, a process that generates information about them. Of course transparency can improve the allocation of capital. However, when the information about the firm affects the terms under which the firm transacts with its customers and employees, transparency can have an offsetting negative effect. Under relatively general conditions, good news improves these terms of trade less than bad news worsens them, implying that increased transparency can lower firm value. In addition, we show that transparency can reduce the incentives of firms and stakeholders to undertake relationship specific investments. The negative effects of transparency can lead firms to pass up positive NPV investments that require external funding and to choose more conservative capital structures that they would otherwise choose. These effects should be especially important for technology firms that require a reputation for being on the leading edge.'

    Economic Polarization Through Trade: Trade Liberalization and Regional Growth in Mexico

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    economic growth, regional disparities, trade, integration, polarization, Mexico

    Influence of atomic polarization and horizontal illumination on the Stokes profiles of the He I 10830 multiplet

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    The polarization observed in the spectral lines of the He I 10830 multiplet carries valuable information on the dynamical and magnetic properties of plasma structures in the solar chromosphere and corona, such as spicules, prominences, filaments, emerging magnetic flux regions, etc. Here we investigate the influence of atomic level polarization on the emergent Stokes profiles for a broad range of magnetic field strengths, in both 90 degree and forward scattering geometry. We show that, contrary to a widespread belief, the selective emission and absorption processes caused by the presence of atomic level polarization may have an important influence on the emergent linear polarization, even for magnetic field strengths as large as 1000 G. Consequently, the modeling of the Stokes Q and U profiles should not be done by taking only into account the contribution of the transverse Zeeman effect within the framework of the Paschen-Back effect theory, unless the magnetic field intensity of the observed plasma structure is sensibly larger than 1000 G. We point out also that in low-lying optically thick plasma structures, such as those of active region filaments, the (horizontal) radiation field generated by the structure itself may substantially reduce the positive contribution to the anisotropy factor caused by the (vertical) radiation field coming from the underlying solar photosphere, so that the amount of atomic level polarization may turn out to be negligible. Only under such circumstances may the emergent linear polarization of the He I 10830 multiplet in such regions of the solar atmosphere be dominated by the contribution caused by the transverse Zeeman effect.Comment: Accepted for publication in The Astrophysical Journal (It is tentatively scheduled for the ApJ January 20, 2007 issue

    Design of robust controllers for multivariable nonlinear plants

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    This thesis deals with design techniques for robust non-linear multivariable systems. It describes and discusses some design techniques for such systems. First, one-loop-at-a-time design using the root locus method is considered. The disadvantages of this approach are outlined. Next, some gain-schedulmg controllers are designed for each loop. Then, a multivariable optimization approach is taken. Software to find the frequency domain solution of the two-block weightedmixed- sensitivity problem using the Youla Parameterisation and Smith-McMillan form is developed. This two-variable problem decouples into two single-variable problems, corresponding to optimizing at the input and output of the plant. The fundamental limitations and the trade-offs in design are studied at the input and output of the plant. A11 controllers are tested and implemented on the inverted pendulum-cart apparatus, an unstable single-input two-output system
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