| 1. |
- Murari, A., et al.
(författare)
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A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors
- 2024
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Ingår i: Nature Communications. - 2041-1723 .- 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- The objective of thermonuclear fusion consists of producing electricity from the coalescence of light nuclei in high temperature plasmas. The most promising route to fusion envisages the confinement of such plasmas with magnetic fields, whose most studied configuration is the tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one of the main potential showstoppers on the route to a commercial reactor. In this work we report how, deploying innovative analysis methods on thousands of JET experiments covering the isotopic compositions from hydrogen to full tritium and including the major D-T campaign, the nature of the various forms of collapse is investigated in all phases of the discharges. An original approach to proximity detection has been developed, which allows determining both the probability of and the time interval remaining before an incoming disruption, with adaptive, from scratch, real time compatible techniques. The results indicate that physics based prediction and control tools can be developed, to deploy realistic strategies of disruption avoidance and prevention, meeting the requirements of the next generation of devices.
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| 2. |
- Joffrin, E., et al.
(författare)
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Overview of the JET preparation for deuterium-tritium operation with the ITER like-wall
- 2019
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
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Forskningsöversikt (refereegranskat)abstract
- For the past several years, the JET scientific programme (Pamela et al 2007 Fusion Eng. Des. 82 590) has been engaged in a multi-campaign effort, including experiments in D, H and T, leading up to 2020 and the first experiments with 50%/50% D-T mixtures since 1997 and the first ever D-T plasmas with the ITER mix of plasma-facing component materials. For this purpose, a concerted physics and technology programme was launched with a view to prepare the D-T campaign (DTE2). This paper addresses the key elements developed by the JET programme directly contributing to the D-T preparation. This intense preparation includes the review of the physics basis for the D-T operational scenarios, including the fusion power predictions through first principle and integrated modelling, and the impact of isotopes in the operation and physics of D-T plasmas (thermal and particle transport, high confinement mode (H-mode) access, Be and W erosion, fuel recovery, etc). This effort also requires improving several aspects of plasma operation for DTE2, such as real time control schemes, heat load control, disruption avoidance and a mitigation system (including the installation of a new shattered pellet injector), novel ion cyclotron resonance heating schemes (such as the three-ions scheme), new diagnostics (neutron camera and spectrometer, active Alfven eigenmode antennas, neutral gauges, radiation hard imaging systems...) and the calibration of the JET neutron diagnostics at 14 MeV for accurate fusion power measurement. The active preparation of JET for the 2020 D-T campaign provides an incomparable source of information and a basis for the future D-T operation of ITER, and it is also foreseen that a large number of key physics issues will be addressed in support of burning plasmas.
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| 3. |
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Overview of the JET results
- 2015
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 55:10
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Bombarda, F., et al.
(författare)
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Runaway electron beam control
- 2019
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Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 1361-6587 .- 0741-3335. ; 61:1
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Tidskriftsartikel (refereegranskat)
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| 5. |
- Krasilnikov, A., et al.
(författare)
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Evidence of 9 Be + p nuclear reactions during 2ω CH and hydrogen minority ICRH in JET-ILW hydrogen and deuterium plasmas
- 2018
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:2
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Tidskriftsartikel (refereegranskat)abstract
- The intensity of 9Be + p nuclear fusion reactions was experimentally studied during second harmonic (2ω CH) ion-cyclotron resonance heating (ICRH) and further analyzed during fundamental hydrogen minority ICRH of JET-ILW hydrogen and deuterium plasmas. In relatively low-density plasmas with a high ICRH power, a population of fast H+ ions was created and measured by neutral particle analyzers. Primary and secondary nuclear reaction products, due to 9Be + p interaction, were observed with fast ion loss detectors, γ-ray spectrometers and neutron flux monitors and spectrometers. The possibility of using 9Be(p, d)2α and 9Be(p, α)6Li nuclear reactions to create a population of fast alpha particles and study their behaviour in non-active stage of ITER operation is discussed in the paper.
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| 6. |
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- 2018
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:1
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Forskningsöversikt (refereegranskat)
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| 31. |
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- 2018
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:9
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Tidskriftsartikel (refereegranskat)
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| 32. |
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| 33. |
- Litaudon, X., et al.
(författare)
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EUROfusion contributions to ITER nuclear operation
- 2024
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Ingår i: Nuclear Fusion. - : Institute of Physics Publishing (IOPP). - 0029-5515 .- 1741-4326. ; 64:11
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Tidskriftsartikel (refereegranskat)abstract
- ITER is of key importance in the European fusion roadmap as it aims to prove the scientific and technological feasibility of fusion as a future energy source. The EUROfusion consortium of labs within Europe is contributing to the preparation of ITER scientific exploitation and operation and aspires to exploit ITER outcomes in view of DEMO. The paper provides an overview of the major progress obtained recently, carried out in the frame of the new (initiated in 2021) EUROfusion work-package called 'Preparation of ITER Operation' (PrIO). The overview paper is directly supported by the eleven EUROfusion PrIO contributions given at the 29th Fusion Energy Conference (16-21 October 2023) London, UK [www.iaea.org/events/fec2023]. The paper covers the following topics: (i) development and validation of tools in support to ITER operation (plasma breakdown/burn-through with evolving plasma volume, new infra-red synthetic diagnostic for off-line analysis and wall monitoring using Artificial Intelligence techniques, synthetic diagnostics development, development and exploitation of multi-machine databases); (ii) R&D for the radio-frequency ITER neutral beam sources leading to long duration of negative deuterium/hydrogen ions current extraction at ELISE and participation in the neutral beam test facility with progress on the ITER source SPIDER, and, the commissioning of the 1 MV high voltage accelerator (MITICA) with lessons learned for ITER; (iii) validation of neutronic tools for ITER nuclear operation following the second JET deuterium-tritium experimental campaigns carried out in 2021 and in 2023 (neutron streaming and shutdown dose rate calculation, water activation and activated corrosion products with advanced fluid dynamic simulation; irradiation of several materials under 14.1 MeV neutron flux etc).
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| 34. |
- Plompen, A. J. M., et al.
(författare)
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The joint evaluated fission and fusion nuclear data library, JEFF-3.3
- 2020
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 56:7
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Forskningsöversikt (refereegranskat)abstract
- The joint evaluated fission and fusion nuclear data library 3.3 is described. New evaluations for neutron-induced interactions with the major actinides 235U, 238U and 239Pu, on 241Am and 23Na, 59Ni, Cr, Cu, Zr, Cd, Hf, W, Au, Pb and Bi are presented. It includes new fission yields, prompt fission neutron spectra and average number of neutrons per fission. In addition, new data for radioactive decay, thermal neutron scattering, gamma-ray emission, neutron activation, delayed neutrons and displacement damage are presented. JEFF-3.3 was complemented by files from the TENDL project. The libraries for photon, proton, deuteron, triton, helion and alpha-particle induced reactions are from TENDL-2017. The demands for uncertainty quantification in modeling led to many new covariance data for the evaluations. A comparison between results from model calculations using the JEFF-3.3 library and those from benchmark experiments for criticality, delayed neutron yields, shielding and decay heat, reveals that JEFF-3.3 performes very well for a wide range of nuclear technology applications, in particular nuclear energy.
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| 35. |
- Claudi, R., et al.
(författare)
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SPHERE dynamical and spectroscopic characterization of HD142527B
- 2019
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 622
-
Tidskriftsartikel (refereegranskat)abstract
- Aims. HD142527 is one of the most frequently studied Herbig Ae/Be stars with a transitional disk that hosts a large cavity that is up to about 100 au in radius. For this reason, it has been included in the guaranteed time observation (GTO) SpHere INfrared survey for Exoplanets (SHINE) as part of the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) at the Very Large Telescope (VLT) in order to search for low-mass companions that might explain the presence of the gap. SHINE is a large survey within about 600 young nearby stars are observed with SPHERE with the aim to constrain the occurrence and orbital properties of the giant planet population at large (>5 au) orbital separation around young stars. Methods. We used the IRDIFS observing mode of SPHERE (IRDIS short for infrared dual imaging and spectrograph plus IFS or integral field spectrograph) without any coronagraph in order to search for and characterize companions as close as 30 mas of the star. Furthermore, we present the first observations that ever used the sparse aperture mask (SAM) for SPHERE both in IRDIFS and IRDIFS_EXT modes. All the data were reduced using the dedicated SPHERE pipeline and dedicated algorithms that make use of the principal component analysis (PCA) and reference differential imaging (RDI) techniques. Results. We detect the accreting low-mass companion HD142527B at a separation of 73 mas (11.4 au) from the star. No other companions with mass greater than 10 M-J are visible in the field of view of IFS (similar to 100 au centered on the star) or in the IRDIS field of view (similar to 400 au centered on the star). Measurements from IFS, SAM IFS, and IRDIS suggest an M6 spectral type for HD142527B, with an uncertainty of one spectral subtype, compatible with an object of M = 0.11 +/- 0.06 M-circle dot and R = 0.15 +/- 0.07 R-circle dot. The determination of the mass remains a challenge using contemporary evolutionary models, as they do not account for the energy input due to accretion from infalling material. We consider that the spectral type of the secondary may also be earlier than the type we derived from IFS spectra. From dynamical considerations, we further constrain the mass to 0.26(-0.14)(+0.16) , which is consistent with both our spectroscopic analysis and the values reported in the literature. Following previous methods, the lower and upper dynamical mass values correspond to a spectral type between M2.5 and M5.5 for the companion. By fitting the astrometric points, we find the following orbital parameters: a period of P = 35 137 yr; an inclination of i = 121 130 degrees, a value of Omega = 124 135 degrees for the longitude of node, and an 68% confidence interval of similar to 18-57 au for the separation at periapsis. Eccentricity and time at periapsis passage exhibit two groups of values: similar to 0.2-0.45 and similar to 0.45-0.7 for e, and similar to 2015-2020 and similar to 2020-2022 for T-0. While these orbital parameters might at first suggest that HD142527B is not the companion responsible for the outer disk truncation, a previous hydrodynamical analysis of this system showed that they are compatible with a companion that is able to produce the large cavity and other observed features.
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| 36. |
- Flammini, Francesco, Senior Lecturer, 1978-, et al.
(författare)
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LoRa WAN Roaming for Intelligent Shipment Tracking
- 2020
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Ingår i: 2020 IEEE Global Conference on Artificial Intelligence and Internet of Things, GCAIoT 2020. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728184203
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Konferensbidrag (refereegranskat)abstract
- Intelligent transport systems will be increasingly adopting the Internet of Things as a key enabling technology. LoRa WAntechnology is one of the most popular long-range wireless technologies with a huge potential in applications such as intelligent shipment tracking. This paper addresses the problem of roaming between multiple cooperative shipping companies and their LoRaWAN networks. The proposed roaming improvement is currently in the testing phase. This paper provides an overview of how to expand LoRa WAnroaming with the support of Artificial Intelligence for providing additional services.
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| 37. |
- Moro, Fabio, et al.
(författare)
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Nuclear analysis of the ITER radial neutron camera architectural options
- 2017
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Ingår i: Fusion engineering and design. - : ELSEVIER SCIENCE SA. - 0920-3796 .- 1873-7196. ; 123, s. 1033-1038
-
Tidskriftsartikel (refereegranskat)abstract
- The ITER Radial Neutron Camera (RNC) is a multichannel detection system hosted in the Equatorial Port Plug 1 (EPP 1) designed to provide information on the neutron source total strength arid emissivity profiles. It consists of two sub-systems: the ex-port line-of-sights (LOSs), covering the plasma core, embedded in a massive shielding block located in the Port Interspace, and the in-port LOSs distributed in two removable cassettes integrated inside the Port Plug. Presently, the RNC layout development process is undergoing a System Level Design phase: several preliminary architectural options based on a System Engineering work have been defined: a detailed nuclear analysis of these options has been performed through radiation transport calculations with the MCNP Monte Carlo code. The radiation environment at the detectors positions has been fully characterized through the evaluation of the expected neutron spectra and the secondary gamma background and the analysis of the 3D radiation maps. MoreOver, the impact of a reduced ex-port shielding block on the neutron and gamma spectra has been investigated. The results of the present study provide guidelines for the development of the RNC final design and the necessary data for the measurement performance analysis.
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| 38. |
- Pasetti, M., et al.
(författare)
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Evaluation of the use of class B LoraWAn for the coordination of distributed interface protection systems in smart grids
- 2020
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Ingår i: Journal of Sensor and Actuator Networks. - : MDPI AG. - 2224-2708. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- The adoption of the distributed generation paradigm is introducing several changes in the design and operation of modern distribution networks. Modern grid codes are becoming more and more complex, and the adoption of smart protection systems is becoming mandatory. However, the adoption of newer and smarter units is only half of the story. Proper communication networks must be provided as well, and the overall costs may become critical. In this work, the adoption of the Long-Range Wide Area Network (LoRaWAN) technology is suggested as a viable approach to implement the coordination of Interface Protection Systems. A proper communication architecture based on the LoRaWAN Class B technology was proposed and evaluated in order to assess its feasibility for the considered application. A scalability analysis was carried out, by computing the number of devices that can be handled by a single LoRaWAN Gateway (GW) and the maximum expected time of response between a triggering event and the arrival of the related coordination command. The results of the study showed that up to 312 devices can be managed by a single GW, by assuring a maximum response time of 22.95 s. A faster maximum response time of 6.2 s is also possible by reducing the number of managed devices to 12. © 2020 by the authors.
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| 39. |
- Rinaldi, S., et al.
(författare)
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Design of a Time Dissemination System Using Chirp Modulation for Medium Voltage Smart Grid Applications
- 2020
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : Institute of Electrical and Electronics Engineers Inc.. - 0018-9456 .- 1557-9662. ; 69:9, s. 6686-6695
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Tidskriftsartikel (refereegranskat)abstract
- The monitoring and the management of smart grid require an advanced communication infrastructure. The time synchronization is among the most important services such an infrastructure should offer. Several solutions are available to disseminate the time information in a distributed system; for instance, most of the times a global positioning system (GPS) receiver is used to recover accurate time information. However, GPS receivers need a clear view of the sky. Other solutions, like the use of a network-based synchronization mechanism, require a dedicated communication infrastructure, which is not always feasible for economical reason. Thus, the use of the power grid itself to disseminate a time signal is extremely interesting. The aim of this article is to investigate the possibility to distribute a time signal over a medium voltage (MV) grid using a chirp-based modulation. The timing data are coded using IRIG-B time code. Such an approach does not require the installation of a dedicated infrastructure, and it is noninvasive, because the signal is transmitted on a different band with the respect to power line communication (PLC). The effectiveness of the approach has been experimentally evaluated on a test MV line available in a laboratory. Although the tested chirp-based symbol has a limited frequency bandwidth (80 kHz), the jitter in the identification of the start of frame is on the order of 7.5 μ s, fulfilling the requirements of the most smart grid applications. © 1963-2012 IEEE.
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| 40. |
- Aissani, D., et al.
(författare)
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Editorial
- 2017
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Ingår i: International Journal of Critical Computer-Based Systems. - : Interscience Communications. - 1757-8779 .- 1757-8787. ; 7:1, s. 1-3
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Tidskriftsartikel (refereegranskat)
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| 41. |
- Aissani, D., et al.
(författare)
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Editorial
- 2017
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Ingår i: International Journal of Critical Computer-Based Systems. - : Interscience Communications. - 1757-8779 .- 1757-8787. ; 7:1, s. 1-3
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 42. |
- Bonafini, F., et al.
(författare)
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Evaluating indoor and outdoor localization services for LoRaWAN in Smart City applications
- 2019
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Ingår i: Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728104294 ; , s. 300-305
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Konferensbidrag (refereegranskat)abstract
- Nowadays, wireless technologies penetrate all aspects of our lives. 'Internet of Things' (IoT) and 'Location- Based Services' are the pillars of Smart City concept. The IoT smart objects surrounding us are an integral part of the Internet, thanks to their computational and communication capabilities. In such applications, location information can be exploited in all the layers of the stack, from the application level (e.g., to correctly interpret measurements from sensor nodes deployed on the field), down to the physical level (e.g., for sensing coverage). One of the most viable solutions for Smart City wireless connectivity seems to be the use of long-range, low-power and low-throughput low-power wide area networks (LPWANs). In this work, the authors devise the jointly use of LPWANs with widely-diffused and well-accepted localization techniques, as the Global Positioning Systems (GPS, outdoor) and real-time location systems (RTLS, indoor), for Smart Campus applications. In particular, a LoRaWAN node equipped with both GPS and Ultra Wide Bandbased UWB-RTLS has been developed and tested in real-world scenarios. Experimental results demonstrate the feasibility of the proposed approach; in particular, location errors are in the order of few tens of meters for GPS and in the order of few tens of centimeters for UWB. © 2019 IEEE.
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| 43. |
- Carvalho, D. F., et al.
(författare)
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Architecture for the interconnection of prototypical medical instrument via cloud services
- 2019
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Ingår i: Proceedings. - 9781538634608
-
Konferensbidrag (refereegranskat)abstract
- Medical cyber-physical systems (MCPS) have been appeared as a possible approach for detecting and mitigating human errors. In this context, a MCPS in which medical and non-medical devices are connected could promptly detect potential risky or wrong procedures that deviate from standardized approaches. In this work, such a paradigm has been expanded to prototypical diagnostic devices. A distributed platform of such instruments is proposed in order to avoid misdiagnosis: diagnostic instrument send data to a message-oriented middleware, thus allowing technicians and doctors to remotely access test-related information for further processing and for creating an historical database. A Broker has been used for collecting data and distribute them to cloud database and to users. Two of the most diffused protocols, i.e., MQTT and AMQP, have been considered. An experimental setup has been developed to verify performance; time-related metrics confirm that the proposed approach has an end-to-end delay on few hundreds of milliseconds even for geographical scale networks. © 2019 IEEE.
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| 44. |
- Fernandes, C. D., et al.
(författare)
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Hybrid indoor and outdoor localization for elderly care applications with LoRaWAN
- 2020
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Ingår i: Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728153865
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Konferensbidrag (refereegranskat)abstract
- It is common for elderly to experience a decrease in health conditions, limiting independence. Very often, hospitalization is not required and at home assistance is a more effective solution. Ambient assisted living technologies can help in mitigating the need for continuous supervision, enabling the elderly to easily look for help in case of emergency. In this work, the well-known and widespread LoRaWAN communication infrastructure is evaluated for possible complementing indoor and outdoor positioning solutions, in order to alert a remotely-connected caregiver about accidents (e.g., falls). The choice of LoRaWAN is dictated by the capability to implement both private and public infrastructures. Satellite-based systems are addressed for outdoor localization, whereas the demanding task of indoor localization is solved by means of Ultra Wide Band technology. Results demonstrated sub-meter error in a typical indoor scenario, with average communication latency on the order of 700 ms. © 2020 IEEE.
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| 45. |
- Fernandes Carvalho, D., et al.
(författare)
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On the evaluation of application level delays in public LoRaWAN networks
- 2019
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Ingår i: Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728112732
-
Konferensbidrag (refereegranskat)abstract
- The Internet of Things paradigm aims to connect a very large number of smart objects located all around the world for increasing the knowledge about the environment. Low-power wireless communications are compulsory to reduce the smart object invasiveness and ensure reasonable duration of autonomous node. For this reason, several Low-Power Wide-Area Network (LPWAN) technologies have been proposed in the recent past, because of their large range and low consumption. Most notably, the LoRaWAN solution emerged as the most accepted LPWAN and several research works appeared, discussing its advantages and limitations. However, very few, if any, discuss timing performance in a real scenario, considering not only the wireless frontend but also the wired backend. In this work, the authors implement a real use case based on a public LoRaWAN infrastructure and propose metrics to formally evaluate the delays at the application level (i.e. considering the whole infrastructure as a black box). The result is an average delay in the range 400-700 ms, and the proof that the delay is directly dependent on both the LoRaWAN backend and the connection speed of information endpoints. © 2019 IEEE.
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| 46. |
- Ferrari, P., et al.
(författare)
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Turning old into new : Adding LoRaWAN connectivity to PLC in brownfield installations
- 2021
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Ingår i: 2021 IEEE International Workshop on Metrology for Industry 4.0 and IoT, MetroInd 4.0 and IoT 2021 - Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781665419802 ; , s. 665-670
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Konferensbidrag (refereegranskat)abstract
- Industry 4.0 paradigm improves industrial automation systems efficiency leveraging on the Industrial Internet of Things (IIoT), offering pervasive connectivity with field devices and paving the way to innovative services. Updating legacy machines in brownfield installations is needed for preserving investments. This paper discusses the design and the experimental validation in a real-world use case of a low-cost solution aiming at providing LoRaWAN Class A connectivity to a Programmable Logic Controller (PLC). Widespread modules, offering full compatibility with the standard, are considered. They behave as 'modems' controlled by AT-like commands via simple serial links (RS232), minimizing the need for additional glue logic. The developed solution has been connected to a public LoRaWAN infrastructure, showing average uplink delays in the order of 300-500 ms; on the contrary, downlink messages are constrained by uplink interarrival time. The experiments also highlighted strong correlation between the LoRaWAN network congestion and the end-to-end delay. © 2021 IEEE.
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| 47. |
- Kiran, P., et al.
(författare)
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Machine learning based 64-QAM classification techniques for enhanced optical communication
- 2023
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Ingår i: Optical and quantum electronics. - : Springer. - 0306-8919 .- 1572-817X. ; 55:13
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Tidskriftsartikel (refereegranskat)abstract
- Due to their greatly increased spectrum efficiency, high-order quadrature amplitude modulation (QAM) formats are especially successful at increasing transmission capacity. QAM is extremely sensitive to nonlinear distortion because of its dense constellation and SNR-hungry configuration. Autonomous neural network (ANN) derived nonlinear decision boundaries that are adaptively created by machine learning techniques can be used to classify symbols. The proposed work focusing on the quadrature amplitude modulation (QAM) scheme, the approach is to formulate an autonomous neural network (ANN) that can predict the class of each symbol from a signal stream of symbols. Experimental accuracy for each ANN's of proposed work achieves 89% by analysing all tests. Comprehensive results are presented with comparisons, demonstrating notable nonlinear mitigation with BER reductions. Additionally, it offers a glimpse into potential future research plans intended to raise the likelihood that predictions would come true and their accuracy.
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| 48. |
- Pasetti, M., et al.
(författare)
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On the Use of Synchronized LoRaWAN for the Coordination of Distributed Energy Resources in Smart Grids
- 2019
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Ingår i: Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9788887237450
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Konferensbidrag (refereegranskat)abstract
- The recent advances in Information and Communication Technology (ICT) are laying down the foundations of future energy systems. The growing availability of reliable and cost-effective ICT solutions are indeed offering the opportunity for the implementation of advanced monitoring and control functions over Distributed Energy Resources (DERs), thus fostering the transition towards decentralized and decarbonized energy systems. The integration of ICT in electrical equipment (such as power converters, metering devices, and protections) is essential for the monitoring and the coordinated control of heterogeneous energy resources, particularly in intermittent and distributed scenarios. Nevertheless, the implementation of such control approaches relies, in the end, on the availability of proper communication infrastructures. The adoption of wired infrastructures (such as field-bus, ethernet, or fiber optic systems) may however imply high installation costs, particularly for complex end-users' systems. To cope with this issue, in this study the use of a wireless network based on the LoRaWAntechnology is proposed to implement the monitoring and the coordinated control of dispersed DERs. A proper communication architecture is proposed and discussed in terms of the required coverage range and latency. Finally, a scalability analysis is also presented, which aims at evaluating the number of devices that can be supervised by a single LoRaWAngateway, by considering the expected data throughput, and the duty cycle limitations. © 2019 AEIT.
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| 49. |
- Rinaldi, S., et al.
(författare)
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An experimental characterization of time of arrival accuracy for time synchronization of medium voltage smart grid solutions
- 2019
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Ingår i: AMPS 2019 Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728100753
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Konferensbidrag (refereegranskat)abstract
- The time synchronization of smart grid devices is a critical feature for the successful application of advanced grid monitoring and control techniques. Synchronization mechanisms based on the accurate estimation of the Time of Arrival (ToA) of network messages-sent over power line cables-are a promising solution to achieve synchronization tasks over distribution lines. In this paper, a chirp-based synchronization technique over the Medium Voltage (MV) grid has been proposed and characterized. Such approach has the benefit of not requiring the installation of a dedicated infrastructure, thanks to the exploitation of power distribution lines for the transmission of time synchronization data. The effectiveness of the approach has been experimentally evaluated on a simplified MV line available in a testing laboratory. Although, the tested chirp has a limited frequency bandwidth (80 kHz), the maximum variation of the ToA estimation is on the order of 3.5 μs, which fulfills the requirements of most smart grid applications. © 2019 IEEE.
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| 50. |
- Rinaldi, S., et al.
(författare)
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Impact of data model on performance of time series database for internet of things applications
- 2019
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Ingår i: Proceedings. - 9781538634608
-
Konferensbidrag (refereegranskat)abstract
- The Internet of Things (IoT) paradigm is gaining interest in several application fields, from medical devices to smart building and industrial automation. Such a success is due to the flexibility and interoperability between different application domains: the possibility to vertically share data among applications is the winning point of this technology. IoT sensors installed on the field generate a large amount of data, which have to be stored somewhere for subsequent analysis. Database technologies are experiencing a deep transformation to be able to handle these data streams. The recent trend is a transition from relational to non-relational databases. Among the latter, the Time Series Databases (TSDBs) seem to be the solution for storing large amount of time series data generated by IoT applications. Although these solutions are optimized to handle thousands of parallel data streams from IoT sensors, the performance of data extraction could not be compatible with some applications. The target of the paper is to investigate the impact that different metadata could have over the data extraction performance in TSDBs. A dedicated testing procedure has been configured for evaluating InfluxDB, one of the most effective and widespread TSDBs. The performance analysis, carried out on a specific use case, demonstrated that the database write and read performance can be significantly affected by the used data model, with queries executed on the same data requiring times from hundreds of ms to seconds in the worst cases. © 2019 IEEE.
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