1,726 research outputs found

    Motion segmentation by consensus

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    We present a method for merging multiple partitions into a single partition, by minimising the ratio of pairwise agreements and contradictions between the equivalence relations corresponding to the partitions. The number of equivalence classes is determined automatically. This method is advantageous when merging segmentations obtained independently. We propose using this consensus approach to merge segmentations of features tracked on video. Each segmentation is obtained by clustering on the basis of mean velocity during a particular time interva

    Bulk viscosity of the massive Gross-Neveu model

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    A calculation of the bulk viscosity for the massive Gross-Neveu model at zero fermion chemical potential is presented in the large-NN limit. This model resembles QCD in many important aspects: it is asymptotically free, has a dynamically generated mass gap, and for zero bare fermion mass it is scale invariant at the classical level (broken through the trace anomaly at the quantum level). For our purposes, the introduction of a bare fermion mass is necessary to break the integrability of the model, and thus to be able to study momentum transport. The main motivation is, by decreasing the bare mass, to analyze whether there is a correlation between the maximum in the trace anomaly and a possible maximum in the bulk viscosity, as recently conjectured. After numerical analysis, I find that there is no direct correlation between these two quantities: the bulk viscosity of the model is a monotonously decreasing function of the temperature. I also comment on the sum rule for the spectral density in the bulk channel, as well as on implications of this analysis for other systems.Comment: v2: 3->3 processes included, conclusions unchanged. Comments and references added. Typos corrected. To appear in Phys. Rev.

    New simulations to qualify eutectic lithium-lead as breeder material

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    Pb17Li is today a reference breeder material in diverse fusion R&D programs worldwide. One of the main issues is the problem of liquid metals breeder blanket behavior. The knowledge of eutectic properties like optimal composition, physical and thermodynamic behavior or diffusion coefficients of Tritium are extremely necessary for current designs. In particular, the knowledge of the function linking the tritium concentration dissolved in liquid materials with the tritium partial pressure at a liquid/gas interface in equilibrium, CT =f(PT ), is of basic importance because it directly impacts all functional properties of a blanket determining: tritium inventory, tritium permeation rate and tritium extraction efficiency. Nowadays, understanding the structure and behavior of this compound is a real goal in fusion engineering and materials science. Atomistic simulations of liquids can provide much information; not only supplementing experimental data, but providing new tests of theories and ideas, making specific predictions that require experimental tests, and ultimately helping to a deeper understandin

    Reference Models for Digital Manufacturing Platforms

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    [EN] This paper presents an integrated reference model for digital manufacturing platforms, based on cutting edge reference models for the Industrial Internet of Things (IIoT) systems. Digital manufacturing platforms use IIoT systems in combination with other added-value services to support manufacturing processes at different levels (e.g., design, engineering, operations planning, and execution). Digital manufacturing platforms form complex multi-sided ecosystems, involving different stakeholders ranging from supply chain collaborators to Information Technology (IT) providers. This research analyses prominent reference models for IIoT systems to align the definitions they contain and determine to what extent they are complementary and applicable to digital manufacturing platforms. Based on this analysis, the Industrial Internet Integrated Reference Model (I3RM) for digital manufacturing platforms is presented, together with general recommendations that can be applied to the architectural definition of any digital manufacturing platform.This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 825631 and from the Operational Program of the European Regional Development Fund (ERDF) of the Valencian Community 2014-2020 IDIFEDER/2018/025.Fraile Gil, F.; Sanchis, R.; Poler, R.; Ortiz Bas, Á. (2019). Reference Models for Digital Manufacturing Platforms. Applied Sciences. 9(20):1-25. https://doi.org/10.3390/app9204433S125920Pedone, G., & Mezgár, I. (2018). Model similarity evidence and interoperability affinity in cloud-ready Industry 4.0 technologies. Computers in Industry, 100, 278-286. doi:10.1016/j.compind.2018.05.003Mehrpouya, M., Dehghanghadikolaei, A., Fotovvati, B., Vosooghnia, A., Emamian, S. S., & Gisario, A. (2019). The Potential of Additive Manufacturing in the Smart Factory Industrial 4.0: A Review. Applied Sciences, 9(18), 3865. doi:10.3390/app9183865Tran, Park, Nguyen, & Hoang. (2019). Development of a Smart Cyber-Physical Manufacturing System in the Industry 4.0 Context. Applied Sciences, 9(16), 3325. doi:10.3390/app9163325Fernandez-Carames, T. M., & Fraga-Lamas, P. (2019). A Review on the Application of Blockchain to the Next Generation of Cybersecure Industry 4.0 Smart Factories. IEEE Access, 7, 45201-45218. doi:10.1109/access.2019.2908780Moghaddam, M., Cadavid, M. N., Kenley, C. R., & Deshmukh, A. V. (2018). Reference architectures for smart manufacturing: A critical review. Journal of Manufacturing Systems, 49, 215-225. doi:10.1016/j.jmsy.2018.10.006Sutherland, W., & Jarrahi, M. H. (2018). The sharing economy and digital platforms: A review and research agenda. International Journal of Information Management, 43, 328-341. doi:10.1016/j.ijinfomgt.2018.07.004Corradi, A., Foschini, L., Giannelli, C., Lazzarini, R., Stefanelli, C., Tortonesi, M., & Virgilli, G. (2019). Smart Appliances and RAMI 4.0: Management and Servitization of Ice Cream Machines. IEEE Transactions on Industrial Informatics, 15(2), 1007-1016. doi:10.1109/tii.2018.2867643Gerrikagoitia, J. K., Unamuno, G., Urkia, E., & Serna, A. (2019). Digital Manufacturing Platforms in the Industry 4.0 from Private and Public Perspectives. Applied Sciences, 9(14), 2934. doi:10.3390/app9142934Digital Manufacturing Platforms, Factories 4.0 and beyondhttps://www.effra.eu/digital-manufacturing-platformsZero Defect Manufacturing Platform Project 2019https://www.zdmp.eu/Zezulka, F., Marcon, P., Vesely, I., & Sajdl, O. (2016). Industry 4.0 – An Introduction in the phenomenon. IFAC-PapersOnLine, 49(25), 8-12. doi:10.1016/j.ifacol.2016.12.002Announcing the IoT Industrie 4.0 Reference Architecturehttps://www.ibm.com/cloud/blog/announcements/iot-industrie-40-reference-architectureVelásquez, N., Estevez, E., & Pesado, P. (2018). Cloud Computing, Big Data and the Industry 4.0 Reference Architectures. Journal of Computer Science and Technology, 18(03), e29. doi:10.24215/16666038.18.e29Pisching, M. A., Pessoa, M. A. O., Junqueira, F., dos Santos Filho, D. J., & Miyagi, P. E. (2018). An architecture based on RAMI 4.0 to discover equipment to process operations required by products. Computers & Industrial Engineering, 125, 574-591. doi:10.1016/j.cie.2017.12.029Calvin, T. (1983). Quality Control Techniques for «Zero Defects». IEEE Transactions on Components, Hybrids, and Manufacturing Technology, 6(3), 323-328. doi:10.1109/tchmt.1983.113617

    Industrial Data Services for Quality Control in Smart Manufacturing - the i4Q Framework

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    [EN] This paper presents a new innovative framework to support smart manufacturing quality assurance. More specifically, the i4Q framework provides an IoT-based Reliable Industrial Data Services (RIDS), a complete suite consisting of 22 innovative Solutions, able to manage the huge amount of industrial data coming from cheap cost-effective, smart, and small size interconnected factory devices for supporting manufacturing online monitoring and control. The i4Q Framework guarantees data reliability with functions grouped into five basic capabilities around the data cycle: sensing, communication, computing infrastructure, storage, and analysis-optimization. i4Q RIDS includes simulation and optimization tools for manufacturing line continuous process qualification, quality diagnosis, reconfiguration and certification for ensuring high manufacturing efficiency, leading to an integrated approach to zero-defect manufacturing. This paper presents the main principles of the i4Q framework and the relevant industrial case studies on which it will be evaluated.This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 958205Karakostas, A.; Poler, R.; Fraile Gil, F.; Vrochidis, S. (2021). Industrial Data Services for Quality Control in Smart Manufacturing - the i4Q Framework. IEEE. 454-457. https://doi.org/10.1109/MetroInd4.0IoT51437.2021.948849045445

    The influence of wildfires on aerosol size distributions in rural areas

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    The number of particles and their size distributions were measured in a rural area, during the summer, using a PCASP-X. The aim was to study the influence of wildfires on particle size distributions. The comparative studies carried out reveal an average increase of around ten times in the number of particles in the fine mode, especially in sizes between 0.10 and 0.14 μm, where the increase is of nearly 20 times. An analysis carried out at three different points in time--before, during, and after the passing of the smoke plume from the wildfires--shows that the mean geometric diameter of the fine mode in the measurements affected by the fire is smaller than the one obtained in the measurements carried out immediately before and after (0.14 μm) and presents average values of 0.11 μm.publishe

    Sacubitril-valsartan in heart failure and multimorbidity patients

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    Aims The poor control of symptoms in patients with advanced heart failure with reduced ejection function (HFrEF) can limit the functionality of patients. Sacubitril–valsartan, compared with enalapril, has been shown to reduce mortality and hospitalization, and nowadays, there is still little evidence about the improvement on functionality. The aim of our study is to analyse the improvement of the functional class and the 6 min walking test (6MWT) in patients with multiple pathologies and advanced heart failure. Methods and results From September 2016 to March 2018, 65 multimorbidity patients with severe symptomatic HFrEF were initiated to receive sacubitril–valsartan. Mean age was 78.6 ± 7.4 years, and 68% were male. The Charlson co-morbidity index was 8 points. Seventy-four per cent had New York Heart Association (NYHA) Functional Class IV. After the treatment, patients were able to achieve 55.68 m or more on 6MWT, and 91% presented an improvement in the NYHA functional class. Conclusions Sacubitril–valsartan relieves symptoms and improves functional class prognostic risk of patients with advanced HFrEF and co-morbidit

    Nuclear structure of Ac-231

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    The low-energy structure of 231Ac has been investigated by means of gamma ray spectroscopy following the beta-decay of 231Ra. Multipolarities of 28 transitions have been established by measuring conversion electrons with a mini-orange electron spectrometer. The decay scheme of 231Ra --> 231Ac has been constructed for the first time. The Advanced Time Delayed beta-gamma-gamma(t) method has been used to measure the half-lives of five levels. The moderately fast B(E1) transition rates derived suggest that the octupole effects, albeit weak, are still present in this exotic nucleus

    Faint calcium-rich transient from the double-detonation of a 0.6M0.6\,M_\odot carbon-oxygen white dwarf star

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    We have computed a three-dimensional hydrodynamic simulation of the merger between a massive (0.4M0.4\,M_\odot) helium white dwarf (He WD) and a low-mass (0.6M0.6\,M_\odot) carbon-oxygen white dwarf (CO WD). Despite the low mass of the primary, the merger triggers a thermonuclear explosion as a result of a double detonation, producing a faint transient and leaving no remnant behind. This type of event could also take place during common-envelope mergers whenever the companion is a CO WD and the core of the giant star has a sufficiently large He mass. The spectra show strong Ca lines throughout the first few weeks after the explosion. The explosion only yields <0.01M<0.01\,M_\odot of 56^{56}Ni, resulting in a low-luminosity SN Ia-like lightcurve that resembles the Ca-rich transients within this broad class of objects, with a peak magnitude of Mbol15.7M_\mathrm{bol} \approx -15.7\,mag and a rather slow decline rate of Δm15bol1.5\Delta m_{15}^\mathrm{bol}\approx 1.5\,mag. Both, its lightcurve-shape and spectral appearance, resemble the appearance of Ca-rich transients, suggesting such mergers as a possible progenitor scenario for this class of events.Comment: Submitted to A&A letters, posted on ArXiv after positive referee report. 7 pages, 4 figure
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