3,578 research outputs found

    A Webibliomining Analysis of PPC in the Perspective of Creating an Educational Software for Brazilian University Education

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    The teaching of practical subjects such as PPC (Production Planning and Control) can be enhanced through the use of suitable educational software as it engenders aspects of dynamism and interactivity in the learning process. The present article aims to develop a webibliomining analysis in order to expose the theoretical framework and to explain the state of art of research related to PPC in scientific literature. The key content of PPC topics will be used as a guideline for the development of an specific educational software framework. As for the methodology, bibliographic and bibliometric research resources were used to compose the webibliomining analysis, thus making the article acquire the character of qualitative and quantitative research. The renowned Web of Science database and Nails software were used in order to formulate and prioritize the PPC content. As a result of this, the product of the article consists of the framework of the referred software which has highly relevant content because it is aligned with the inputs generated by the use of webibliomining resource as a facilitating tool on content selection of PPC subjects seeking to increase the learning process efficiency by students of engineering and business at Brazilian universities

    TGF afterglows: A new radiation mechanism from thunderstorms

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    Thunderstorms are known to create terrestrial gamma ray flashes (TGFs) which are microsecond-long bursts created by runaway of thermal electrons from propagating lightning leaders, as well as gamma ray glows that possibly are created by relativistic runaway electron avalanches (RREA) that can last for minutes or more and are sometimes terminated by a discharge. In this work we predict a new intermediate thunderstorm radiation mechanism, which we call TGF afterglow, as it is caused by the capture of photonuclear neutrons produced by a TGF. TGF afterglows are milliseconds to seconds long; this duration is caused by the thermalization time of the intermediate neutrons. TGF afterglows indicate that the primary TGF has produced photons in the energy range of 10-30 MeV; they are nondirectional in contrast to the primary TGF. Gurevich et al. might have reported TGF afterglows in 2011

    Spatial clustering of molecular dynamics trajectories in protein unfolding simulations

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    Molecular dynamics simulations is a valuable tool to study protein unfolding in silico. Analyzing the relative spatial position of the residues during the simulation may indicate which residues are essential in determining the protein structure. We present a method, inspired by a popular data mining technique called Frequent Itemset Mining, that clusters sets of amino acid residues with a synchronized trajectory during the unfolding process. The proposed approach has several advantages over traditional hierarchical clustering.The authors acknowledge the support of the "Fundacao para a Ciencia e Tecnologia,Portugal, and the program FEDER, through grant PTDC/BIA-PRO/72838/2006 (to PJA and RMMB) and the Fellowships SFRH/BPD/42003/2007(to PGF) and SFRH/BD/16888/2004 (to CGS). We thank the Center for Computational Physics, Departamento de Fisica, Universidade de Coimbra, for the computer resources provided for the MD simulations

    Mining approximate motifs in time series

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    The problem of discovering previously unknown frequent patterns in time series, also called motifs, has been recently introduced. A motif is a subseries pattern that appears a significant number of times. Results demonstrate that motifs may provide valuable insights about the data and have a wide range of applications in data mining tasks. The main motivation for this study was the need to mine time series data from protein folding/unfolding simulations. We propose an algorithm that extracts approximate motifs, i.e. motifs that capture portions of time series with a similar and eventually symmetric behaviour. Preliminary results on the analysis of protein unfolding data support this proposal as a valuable tool. Additional experiments demonstrate that the application of utility of our algorithm is not limited to this particular problem. Rather it can be an interesting tool to be applied in many real world problems.Fundação para a Ciência e a Tecnologia (FCT).Fundo Europeu de Desenvolvimento Regional (FEDER) - POCTI/BME/49583/2002; SFRH/BD/13462/2003; SFRH/BD/16888/2004

    Reducing scrap and improving an air conditioning pipe production line

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    30th International Conference on Flexible Automation and Intelligent Manufacturing (FAIM2021) -15-18 June 2021, Athens, GreeceThe automotive industry is considered one of the most demanding and competitive sectors in the global market. This increasingly implies having a stable and optimized production process, always with a view to continuous improvement. Therefore, it is very important to be aware of all the waste that is generated in all production and logistics operations and take action to reduce them. In this regard and considering the process of producing air conditioning pipes for the automotive industry, a high scrap value was detected mainly due to soldering process. Therefore, the entire production process is analyzed in order to identify the main causes behind the high scrap value. Several Lean and quality tools are used to reduce not only the amount of scrap but also to increase the line productivity. In order to face this challenge, after elaborating the action plan and corresponding implementation, the scrap value is reduced by 12% in general, and productivity increased by 29%, 55% and 22.5% in three different references produced by the same machine. Although this solution is a bit expensive, the corresponding payback is reduced, so it can easily be applied transversally to other similar machines allowing extremely interesting gains in the short term.Andresa Baptista acknowledges the financial support of CIDEM- Research Center of Mechanical Engineering, FCT –Portuguese Foundation for the Development of Science and Technology, Ministry of Science, Technology and Higher ducation, under the Project UID/EMS/0615/2019.info:eu-repo/semantics/publishedVersio

    A taxonomic reassessment of Piramys auffenbergi, a neglected turtle from the late Miocene of Piram Island, Gujarat, India

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    Piramys auffenbergi was described as an emydine turtle based on a well-preserved skull retrieved from late Miocene deposits exposed on Piram Island, India. The description and figures provided in the original publication are vague and do not support assignment to Emydinae. This taxon has mostly been ignored by subsequent authors.Material and Methods: We reexamine the holotype specimen, provide an extensive description and diagnosis for Piramys auffenbergi, and include this taxon in a global character-taxon matrix for Pleurodira.Results: The presence of a processus trochlearis pterygoidei conclusively shows pleurodiran affinities for Piramys auffenbergi. Inclusion of this taxon in a phylogenetic analysis retrieves it within Stereogenyini closely related to the Asian taxa Shweboemys pilgrimi and Brontochelys gaffneyi.Discussion: Our reexamination of the holotype of Piramys auffenbergi confidently rejects the original assessment of this taxon as an emydine testudinoid and conclusively shows affinities with the pleurodiran clade Stereogenyini instead. Even though most taxa from this lineage are thought to be coastal turtles, all Asian stereogenyines were collected from continental deposits, suggesting a more diverse paleoecology for the group

    Hábitos alimenticios de la rana bromélicola Phyllodytes edelmoi Peixoto, Caramaschi & Freire, 2003 (Anura: Hylidae) del Estado de Alagoas, Noreste de Brasil

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    El género de hílidos Phyllodytes está compuesto por 12 especies distribuidas en el este de Brasil y conocidas por habitar estrictamente bromeliáceas. En este estudio se exploran los hábitos alimenticios de P. edelmoi y se testea la selectividad de las presas por la especie comparando las presas encontradas en los estómagos con la disponibilidad de presas en las bromelias. Nuestros resultados muestran que P. edelmoi consume grandes cantidades de hormigas a lo largo del año, por lo que podría considerarse una especie "especializada en hormigas". Este comportamiento alimenticio especializado podría ser considerado una sinapomorfia para el género Phyllodytes.The hylid frog genus Phyllodytes comprised 12 species distributed in eastern Brazil and knownto strictly inhabit inside bromeliads. In this study, we explore the feeding habits of P. edelmoiand test the prey selectivity of the species by comparing the prey items in the stomachs contentswith the availability of preys in bromeliads. Our results show that P. edelmoi consumes highamounts of ants along the year, and therefore it could be considered an ?ant specialist? species.This specialist feeding behaviour could be considered a synapomorphy of the genus Phyllodytes.Fil: Araujo-Vieira, Katyuscia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Ubiratan G. Silva. Universidade Federal de Alagoas; BrasilFil: Jhonatan Guedes dos Santos. Universidade Federal de Alagoas; BrasilFil: Thame G. Ferreira. Departamento de Ecologia E Biomonitoramento; BrasilFil: Gabriel O. Skuk. Universidade Federal de Alagoas; Brasi

    Human-AI Co-Creation Approach to Find Forever Chemicals Replacements

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    Generative models are a powerful tool in AI for material discovery. We are designing a software framework that supports a human-AI co-creation process to accelerate finding replacements for the ``forever chemicals''-- chemicals that enable our modern lives, but are harmful to the environment and the human health. Our approach combines AI capabilities with the domain-specific tacit knowledge of subject matter experts to accelerate the material discovery. Our co-creation process starts with the interaction between the subject matter experts and a generative model that can generate new molecule designs. In this position paper, we discuss our hypothesis that these subject matter experts can benefit from a more iterative interaction with the generative model, asking for smaller samples and ``guiding'' the exploration of the discovery space with their knowledge.Comment: 5 pages, Generative AI and HCI (GenAICHI) Workshop at CHI 23 (ACM CHI Conference on Human Factors in Computing Systems

    Effect of proximity-induced spin-orbit coupling in graphene mesoscopic billiards

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    van der Waals heterostructures based on two-dimensional materials have recently become a very active topic of research in spintronics, both aiming at a fundamental description of spin dephasing processes in nanostructures and as a potential element in spin-based information processing schemes. Here, we theoretically investigate the magnetoconductance of mesoscopic devices built from graphene proximity-coupled to a high spin-orbit coupling material. Through numerically exact tight-binding simulations, we show that the interfacial breaking of inversion symmetry generates robust weak antilocalization even when the z → −z symmetric spin-orbit coupling in the quantum dot dominates over the Bychkov-Rashba interaction. Our findings are interpreted in the light of random matrix theory, which links the observed behavior of quantum interference corrections to a transition from a circular-orthogonal to circular-symplectic ensemble
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