748 research outputs found
Sort by
FlexRQC: Model for a Flexible Robot-Driven Quality Control Station
Get PDFAs the investment on a dedicated quality control stations is not desirable for limited production batches. In general, those systems result in very optimised systems and the lack of flexibility since they are designed for an ad-hoc production. To provide a solution for those cases, a new model to design a flexible quality inspection system is proposed. This paper introduces FlexRQC (Flexible Robotic Quality Control) a model for characterising flexible robot-driven quality control stations. FlexRQC is divided into two domains: The Quality Control Station Domain (QCSD) and the Model Under Inspection Domains (MUID). FlexRQC takes advantage of 3D CAD systems to get spacial information on the quality control station and the quality requirement. The flexibility of the model has been successfully tested in two quality control station setups and various solid rigid objects
Efectividad percibida de los instrumentos tradicionales e innovadores de rendición de cuentas en España. Análisis comparativo en Andalucía, Euskadi, Cataluña, Galicia, Madrid, y Valencia
Get PDFThe perceived effectiveness of established and innovative media accountability instruments is analyzed in Andalusia, Euskadi, Catalonia, Galicia, Madrid and Valencia, and by means of a survey conducted among journalists, focus groups with media consumers in each community, and in-depth interviews with experts. Some differences are observed across professionals, citizens and experts and amongst the different autonomous communities. Audience participation in media accountability is the most controversial aspect.El presente artículo analiza la efectividad percibida de los instrumentos de rendición de cuentas tradicionales e innovadores en medios de comunicación en Andalucía, Euskadi, Cataluña, Galicia, Madrid y Valencia. La percepción de la efectividad de los mecanismos de rendición de cuentas tradicionales y los nuevos instrumentos se estudia mediante una encuesta a periodistas, focus groups con consumidores de medios en cada comunidad y entrevistas en profundidad con expertos. Los resultados de la investigación muestran diferencias tanto entre estos tres colectivos como entre comunidades autónomas. La participación de la audiencia en la rendición de cuentas es el aspecto más controvertido
The influence of the kinematic hardening on the FEM simulation of Tension Levelling Process
Get PDFTension levelling is used in the steel industry to remove shape defects present in cold rolled strip. This technology is increasingly being employed by steel makers to level AHSS steels, because conventional roll levelers are not able to correct explicit local errors like wavy edges and central buckles. In this study, the influence the hardening law has on the simulation of tension levelling processes using FEM is studied. Tension-compression tests have been performed in a DP1000 steel using several reversal cycles and a mixed nonlinear kinematic hardening law has been fitted to the experimental data using different amount of backstress tensors. It is observed that numerical results are influenced by the introduced hardening law and thus is an important input when simulating the tension levelling process
Mathematical content on STEM activities
Get PDFIn this paper, a number of STEM educational proposals are systematically analyzed from the lens of mathematics education. An extensive innovation project was implemented during the 2019/2020 academic year in a pilot study carried out in Schools and Teacher Training Programs in Navarre (Spain), comprising a bibliographical and source analysis as a previous step to characterize the existing material, and ultimately to design and test STEM projects at different educational levels from the point of view of mathematical education. All activities belong to international publications and widely used and contrasted web repositories, and seize the usual interval of compulsory education, i.e., from the beginning of Primary School (age 6/7) to the end of Secondary School (age 15/16). The findings draw a panorama of STEM activities where mathematics is mostly utilitarian, numbers and units are functionally used to measure quantities of magnitudes, and geometric contents serve the purpose of modeling a technological prototype. As it turns out, some STEM-labelled activities do not fulfill their principles and fundamental purposes. In lower levels, there is a common confusion between STEM activities and science laboratory projects; in higher levels, complex mathematical content could appear. Even though some activities are guided science laboratory projects, it is concluded that most STEM activities have the potential of a-didactical situations, i.e., contexts where students put into practice their personal problem-solving techniques before teachers formalize the mathematical content
Aligning regional and business strategies: Looking inside the Basque Country entrepreneurial innovation ecosystem
Get PDFThe current socio-economic scenarios have generated several challenges for any organization. Regional authorities have designed policies that combine supply–demand needs and innovative entrepreneurship programs. The alignment between
regional and business strategies has become critical to ensure the necessary resources, skills and capabilities in the region. This article analyses the alignment of regional strategies (entrepreneurial innovation ecosystems) and business strategies
(development of new entrepreneurial innovations). By adopting mixed theoretical approaches, we proposed a conceptual model to understand the role of institutional strategies on the definition of business strategies. Given the nature of this study, our
methodological design combines a case study approach and an action research approach. Our results provide insights into the positive outcomes generated when regional strategies and business strategies are aligned
Inclined bodies that imagine
Get PDFThis text links the trajectory of American choreographer Steve Paxton with
specific aspects of the thinking of Adriana Cavarero and Donna Haraway.
For decades, Paxton has researched the human body through the
experience of walking, the study of gravity and the creation of organic
compost. Based on the concept of inclination developed by Adriana
Cavarero, as a relational model in which the self inclines, becomes
destabilised and relates from a state of vulnerability, I will argue that this
awareness allows us to re-experience our relationship with the body and,
therefore, with the world. To incline, to feel gravity and to imagine, opens
different perceptions. They make up a sensibility from which, as in the
creation of organic compost and its microorganisms and microspecies, it is
possible to affect a wider structure. Haraway states that we are all compost,
which leads us to position ourselves closer to the earth and to think of
ourselves as human beings, humus beings: spaces in which others can
grow
Static Current Unbalance of Paralleled SiC MOSFET Modules in the Final Layout
Get PDFSilicon Carbide (SiC) MOSFETs enable enhanced performance of power converters in several applications. Parallel connection of SiC MOSFETs become mandatory for medium power applications due to the current rate of existing modules. A balanced current sharing between paralleled MOSFETs is desired to maximize the power capability of each device, maximizing the power capability of the whole system. This work studies the static current unbalance of two paralleled 1200V-400A SiC MOSFET modules with individual gate driver. Experimental measurements are done focused on parasitic inductance caused by electromechanical layout
In-depth Life Cycle Cost Analysis of a Li-ion Battery-based Hybrid Diesel-Electric Multiple Unit
Get PDFThis study analyzes the life cycle costs of railway projects involving hybrid diesel-electric multiple units, focusing on the influence of lithium-ion battery technologies and energy management strategies. Specifically, 3 lithium-ion battery technologies and 6 energy management strategies are proposed, leading to a sensitivity analysis composed of 18 cases. In addition, for each case an approach for the optimal sizing of the diesel generator and lithium-ion battery is proposed. A scenario based on a real railway line is introduced and the results are compared to a traditional diesel-electric multiple unit. Potential life cycle cost savings of 16.0% are obtained when deploying a global optimization-based energy management strategy and LTO batteries
Linear Machines for Long Stroke Applications: a review
Get PDFThis document reviews the current state of the art in the linear machine technology. First,the recent advancements in linear induction, switched reluctance and permanent magnet machines arepresented. The ladder slit secondary configuration is identified as an interesting configuration for linearinduction machines. In the case of switched reluctance machines, the mutually-coupled configuration hasbeen found to equate the thrust capability of conventional permanent magnet machines. The capabilities ofthe so called linear primary permanent magnet, viz. switched-flux, flux-reversal, doubly-salient and verniermachines are presented afterwards. A guide of different options to enhance several characteristics of linearmachines is also listed. A qualitative comparison of the capabilities of linear primary permanent magnetmachines is given later, where linear vernier and switched-flux machines are identified as the most interestingconfigurations for long stroke applications. In order to demonstrate the validity of the presented comparison,three machines are selected from the literature, and their capabilities are compared under the same conditionsto a conventional linear permanent magnet machine. It is found that the flux-reversal machines suffer froma very poor power factor, whereas the thrust capability of both vernier and switched-flux machines isconfirmed. However, the overload capability of these machines is found to be substantially lower than theone from the conventional machine. Finally, some different research topics are identified and suggested foreach type of machine
Crystal-plasticity-finite-element modeling of the dynamic response of a directionally solidified nickel-based superalloy
No full textThe flow stress behaviour of a directionally solidified nickel-base superalloy,MAR-M247, is presented through the combination of experiments and crystal-plasticity simulations.The experimental campaign encompassed quasi-static and dynamic testing in the parallel andperpendicular orientation with respect to the columnar grains. The material showed low strain-ratesensitivity in all cases. Virtual samples were generated with DREAM3d and each grain orientation wasestablished according to the DS nature of the alloy. The elasto-visco-plastic response of each crystalis given by phenomenological-base equations, considering the dislocation–dislocation interactionsamong different slip systems. The hardening-function constants and the strain-rate sensitivityparameter were fitted with the information from tests parallel to the grain-growth direction and themodel was able to predict with accuracy the experimental response in the perpendicular direction,confirming the suitability of the model to be used as a tool for virtual testing. Simulations alsorevealed that in oligocrystalline structures of this type, the yield-strength value is controlled bythe grains with higher Schmid factor, while this influence decreases when plastic strain increases.Moreover, the analysis of the micro-fields confirmed that grains perpendicular to the loading axis areprone to nucleate cavities since the stresses in these regions can be twice the external applied stress