341 research outputs found

    Higher-order Cartan symmetries in k-symplectic field theory

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    For k-symplectic Hamiltonian field theories, we study infinitesimal transformations generated by certain kinds of vector fields which are not Noether symmetries, but which allow us to obtain conservation laws by means of a suitable generalization of the Noether theorem.Comment: 11 page

    Myths of positive psychology: deceptive manoeuvres and pseudoscience

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    Positive Psychology (PP) has experienced a huge boom in the last twenty years. The aim of this study is to list a number of myths and fallacious argumentative manoeuvres which sow serious doubts about the novelty and originality of PP. The PP discourse is notably pseudoscientific and has a certain intellectual dishonesty. Additionally, PP extends knowledge through social networks, books and journals. This knowledge is alleged to be empirically evidence-based, but in fact it is sustained upon tautological statements, superficial knowledge and obvious conclusions. All of the knowledge produced by PP reveals what it is provided by common sense and traditional wisdom. In conclusion, PP is not necessary in producing this knowledge and is academically and socially irrelevant and dispensable. This paper concludes with some considerations about the uncertain future of the always controversial PP

    PEDESTRIAN PATHFINDING in URBAN ENVIRONMENTS: PRELIMINARY RESULTS

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    With the rise of urban population, many initiatives are focused upon the smart city concept, in which mobility of citizens arises as one of the main components. Updated and detailed spatial information of outdoor environments is needed to accurate path planning for pedestrians, especially for people with reduced mobility, in which physical barriers should be considered. This work presents a methodology to use point clouds to direct path planning. The starting point is a classified point cloud in which ground elements have been previously classified as roads, sidewalks, crosswalks, curbs and stairs. The remaining points compose the obstacle class. The methodology starts by individualizing ground elements and simplifying them into representative points, which are used as nodes in the graph creation. The region of influence of obstacles is used to refine the graph. Edges of the graph are weighted according to distance between nodes and according to their accessibility for wheelchairs. As a result, we obtain a very accurate graph representing the as-built environment. The methodology has been tested in a couple of real case studies and Dijkstra algorithm was used to pathfinding. The resulting paths represent the optimal according to motor skills and safety

    Integration of infrared thermography and photogrammetric surveying of built landscape

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    The thermal analysis of buildings represents a key-step for reduction of energy consumption, also in the case of Cultural Heritage. Here the complexity of the constructions and the adopted materials might require special analysis and tailored solutions. Infrared Thermography (IRT) is an important non-destructive investigation technique that may aid in the thermal analysis of buildings. The paper reports the application of IRT on a listed building, belonging to the Cultural Heritage and to a residential one, as a demonstration that IRT is a suitable and convenient tool for analysing the existing buildings. The purposes of the analysis are the assessment of the damages and energy efficiency of the building envelope. Since in many cases the complex geometry of historic constructions may involve the thermal analysis, the integration of IRT and accurate 3D models were developed during the latest years. Here authors propose a solution based on the up-to-date photogrammetric solutions for purely image-based 3D modelling, including automatic image orientation/sensor calibration using Structure-from-Motion and dense matching. Thus, an almost fully automatic pipeline for the generation of accurate 3D models showing the temperatures on a building skin in a realistic manner is described, where the only manual task is given by the measurement of a few common points for co-registration of RGB and IR photogrammetric projects.Xunta de Galicia | Ref. ED481B 2016/079-
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