3,055 research outputs found
Erratum to: Assessing concrete strength with rebound hammer: review of key issues and ideas for more reliable conclusions
Maneuver Optimization for Simultaneous Airspeed Calibration and Wind Estimation
[EN] The purpose of this work is to optimize systematically the maneuver required to identify the wind and calibrate the airspeed sensor of a subsonic aircraft using a GPS method. The optimization is based on sensitivity analyses that require a considerable number of flight simulations. To face this challenging computational effort, we adapted and parallelized a particle swarm optimization algorithm. We also introduced a new formulation of the sensor model in the Bernstein form. The results show stability using the selected formulation and bring out non-obvious aliasing and precision loss effects that depend on the maneuver configuration. The knowledge of these effects allowed us to fine-tune the maneuver in order to improve the estimation's precision. Finally, we validated the method using the JSBSim flight simulator under calm and light turbulence conditions.S
Optimized profile planar UWB monopole antenna for optimal adaptation
This work deals with the possibility of making a completely blind optimization of th profile of a planar monopole antenna in order to satisfy previously defined demands, in this case minimal return losses for an UWB system. Previous results in this topic were already discussed in [1]. In that work, optimization of the profile of the antenna was not completely blind due to the high computational effort needed to obtain results, which can tirn to be a complete failure. Hence, to speed up the method, the global optimization was performed using a less accurate but quicker analysis and then refining the solution with a local optimization using a very accurate analysis
A study on the microstructural evolution of a low alloy steel by different shot peening treatments
Recent studies have shown that severe shot peening can be categorized as a severe plastic deformation surface treatment that is able to strongly modify the microstructure of the surface layer of materials, by both increasing the dislocation density and introducing a large number of defects that define new grain boundaries and form ultrafine structure. In this work, conventional shot peening and severe shot peening treatments were applied to 39NiCrMo3 steel samples. The samples were characterized in terms of microstructure, surface roughness, microhardness, residual stresses, and surface work-hardening as a function of surface coverage. Particular attention was focused on the analysis of the microstructure to assess the evolution of grain size from the surface to the inner material to capture the gradient microstructure. Severe shot peening proved to cause a more remarkable improvement of the general mechanical characteristics compared to conventional shot peening; more significant improvement was associated with the microstructural alteration induced by the treatment. Our datas provide a detailed verification of the relationship between shot peening treatment parameters and the microstructure evolution from the treated surface to the core material
A web-based application for the management and evaluation of tutoring requests in PBL-based massive laboratories
One important steps in a successful project-based-learning methodology (PBL) is the process of providing the students with a convenient feedback that allows them to keep on developing their projects or to improve them. However, this task is more difficult in massive courses, especially when the project deadline is close. Besides, the continuous evaluation methodology makes necessary to find ways to objectively and continuously measure students' performance without increasing excessively instructors' work load. In order to alleviate these problems, we have developed a web service that allows students to request personal tutoring assistance during the laboratory sessions by specifying the kind of problem they have and the person who could help them to solve it. This service provides tools for the staff to manage the laboratory, for performing continuous evaluation for all students and for the student collaborators, and to prioritize tutoring according to the progress of the student's project. Additionally, the application provides objective metrics which can be used at the end of the subject during the evaluation process in order to support some students' final scores. Different usability statistics and the results of a subjective evaluation with more than 330 students confirm the success of the proposed application
Iberos en el Alto Guadalquivir: singularidad y complejidad del poblamiento ibérico en torno a la Depresión Linares Bailén (Jaén)
The Iron Age studies in the upper Guadalquivir have always been an important model used to ascertain the idiosyncrasy of the Iberian culture. In fact, most of the interpretations that allow us to conceive its social, political and economic organization come from the archaeological investigations carried out in this geographical area. However, there is still a long way to go. The in-depth analysis of the territory framed between the rivers Rumblar and Guadiel, two tributaries of the Guadalquivir, has made it possible to resume old issues and propose changes in the approach to the population model developed in this area and concepts such as oppidum, turris or comunnication roads.This paper presents all these new data and outlines the construction of a different Iberian landscape from which, exclusively, small evidence is preserved.Los estudios de la Edad del Hierro en el Alto Guadalquivir han sido siempre un gran referente para conocer la idiosincrasia de la cultura ibera. De hecho, la mayor parte de las interpretaciones que permiten imaginar su modo de organización social, político y económico proceden de las investigaciones arqueológicas realizadas en esta área geográfica. Sin embargo, queda todavía un largo camino por recorrer. El análisis en profundidad del territorio enmarcado entre los ríos Rumblar y Guadiel, dos afluentes del Guadalquivir, ha permitido retomar viejas cuestiones y plantear cambios de enfoque en torno al modelo de poblamiento desarrollado y sobre conceptos como oppidum, turris o vía de comunicación. Este artículo presenta todos estos nuevos datos y esboza la construcción de un paisaje ibero diferente del que, exclusivamente, se conservan pequeñas evidencias
Does Partisan Bias Modulate Neural Processing of Political Information? An Analysis of the Neural Correlates of Corruption and Positive Messages
Daily worldwide newspapers print articles exposing government corruption. Yet these messages do not lead to a loss of votes for the corrupt parties. Sympathizers’ partisan bias, which respectively minimizes and maximizes corruption and positive messages of their own parties respectively, is widely considered the main cause of the loss of effectiveness of political communications. Despite the well-established existence of such bias when processing political information, little is known as to its psychological origin. Through the use of neuroscience (fMRI), this study explores the underlying brain mechanisms of negative (corruption) and positive political messages related to a conservative and a socialist Spanish political party, as well as the differences between their sympathizers. The findings reveal that negative (vs. positive) political messages exert the greatest neuroimaging impact on the electorate, as shown in aversive, risk, and disappointment-related brain regions. Interestingly, we show that there exists a main partisan bias against opposite parties (and not a positive bias toward one’s own party) that stems from a higher risk, ambiguity, and disbelief provoked by both positive and negative information about rival parties. Furthermore, this bias was more pronounced among conservative supporters. The current findings provide valuable insights for political parties to improve their communication campaigns.2018-1
Sistema de presentación de antígenos basado en el virus de la sharka
Referencia OEPM: P9800623.-- Fecha de solicitud: 24/03/1998.-- Titulares: Inmunología y Genética Aplicada, S.A., Consejo Superior de Investigaciones Científicas (CSIC).El sistema de presentación de antígenos heterólogos basado en el virus de la sharka (PPV) comprende una partícula de PPV quimérica formada por ensamblaje de la proteína de la cápsida (CP) de PPV modificada que contiene, al menos, un antígeno heterólogo en dicha CP modificada, estando dicho antígeno dispuesto en la superficie exterior de dicha partícula viral de PPV. Preferentemente, dicho antígeno heterólogo se encuentra en el extremo amino terminal de la CP modificada de PPV. En una realización concreta se describe la construcción de un sistema de presentación de un epítopo inmunológicamente activo derivado de la proteína VP2 del parvovirus canino (CPV). Estos sistemas de presentación de antígenos tienen utilidad en diagnóstico y vacunas.Peer reviewe
Particle Swarm Optimization and Uncertainty Assessment in Inverse Problems
Most inverse problems in the industry (and particularly in geophysical exploration) are highly underdetermined because the number of model parameters too high to achieve accurate data predictions and because the sampling of the data space is scarce and incomplete; it is always affected by different kinds of noise. Additionally, the physics of the forward problem is a simplification of the reality. All these facts result in that the inverse problem solution is not unique; that is, there are different inverse solutions (called equivalent), compatible with the prior information that fits the observed data within similar error bounds. In the case of nonlinear inverse problems, these equivalent models are located in disconnected flat curvilinear valleys of the cost-function topography. The uncertainty analysis consists of obtaining a representation of this complex topography via different sampling methodologies. In this paper, we focus on the use of a particle swarm optimization (PSO) algorithm to sample the region of equivalence in nonlinear inverse problems. Although this methodology has a general purpose, we show its application for the uncertainty assessment of the solution of a geophysical problem concerning gravity inversion in sedimentary basins, showing that it is possible to efficiently perform this task in a sampling-while-optimizing mode. Particularly, we explain how to use and analyze the geophysical models sampled by exploratory PSO family members to infer different descriptors of nonlinear uncertainty
A multi-agent system for managing adverse weather situations on the road network
The development of traffic management and control strategies to improve traffic flows and road safety is necessary due to the high dynamism of traffic flows. The use of distributed intelligent systems can help the traffic organizations and the road operators to cope with possible incidents on the road network, especially when the incidents are related to adverse meteorological conditions. In that case, the probability of road accidents is increased due to the difficulty of driving under bad weather conditions. So, if the operators detect any meteorological incident, they must decide how to deal with it in order to improve traffic safety. In this paper we introduce a new multiagent system (MAS) to support traffic management when there appear meteorological problems in the road network. MAS technology helps to deal with the specific characteristics of traffic domain. The proposed MAS is able to work in two ways: a) coordinately, where all the agents work to solve weather problems in large networks and b) locally, where due to communications breakdown small groups of agents work together to inform road users about weather problems. The MAS has a rule-based system to deal with the meteorological data and decide the actions to take in front of any meteorological issue. This expert system also controls the quality of the data, improving the road operator confidence in the decisions taken by the expert system. However, weather sensors can provide wrong data, due to several factors (hardware failure, climate factors, etc.) so the rule based system controls these provided data by applying specific coherence and correlation rules to improve the quality of the taken decisions
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