Browsing by Author "Rojas, F."

Now showing 1 - 14 of 14
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    Classifying CMB time-ordered data through deep neural networks
    (2020) Rojas, F.; Maurin, Loïc Benjamin; Dünner Planella, Rolando; Pichara Baksai, Karim Elías
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    Decoupled PI Controllers Based on Pulse-Frequency Modulation for Current Sharing in Multi-Phase LLC Resonant Converters
    (2021) Moreno, M.; Pereda Torres, Javier Eduardo; Rojas, F.; Dominguez-Lopez, I.
    The LLC series resonant converter has emerged as a solution to applications requiring power conversion with isolation, reduced volume and high efficiency, such as PV systems and EV chargers. However, the LLC resonant converter is limited in power, so it requires a multi-phase configuration in order to provide higher currents. This configuration connects the outputs of two or more LLC converters in parallel, increasing the output current but introducing imbalance and circulating currents due to the mismatch and tolerance values of components in each resonant tank. This paper proposes a simple PI control scheme to compensate the current imbalance and eliminate circulating currents generated when several LLC resonant converters are connected in parallel. Unlike reported current sharing methods, the proposed control scheme is based on multiple current control loops operating independently, using the switching frequency of each parallel-connected unit as a degree of freedom of the overall converter. The proposed control scheme has been successfully validated under simulations and experimental assessment, implementing two resonant tanks with ±5% tolerance of parameters, providing excellent steady-state and transient performance.
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    HATS-17b : A TRANSITING COMPACT WARM JUPITER IN A 16.3 DAY CIRCULAR ORBIT
    (2016) Brahm, R.; Jordán Colzani, Andrés Cristóbal; Bakos G.; Penev K.; Espinoza Pérez, Néstor; Rabus, Markus; Hartman J.; Bayliss D.; Ciceri S.; Zhou G.; Mancini, L.; Tan, T.; De Val, M.; Bhatti, W.; Csubry, Z.; Henning, T.; Schmidt, B; Rojas, F.; Suc, V.; Lazar, J.; Papp, I.; Sari, P.
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    HD 1397b : A Transiting Warm Giant Planet Orbiting A V = 7.8 mag Subgiant Star Discovered by TESS
    (2019) Brahm Scott, Rafael; Espinoza Pérez, Néstor; Jordán Colzani, Andrés Cristóbal; Henning, T.; Sarkis, P.; Jones Fernández, Matías Ignacio; Diaz, M.R.; Jenkins, J.S.; Vanzi, Leonardo; Zapata, Abner; Petrovich Balbontín, Cristóbal; Kossakowski, D.; Rabus, Markus; Rojas, F.; Torres, P.
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    Linear Control applied to a non-isolated bidirectional DC-DC converter with Interleave technique powered by variable sources
    (IEEE, 2019) Salgado, J.; Rojas, F.; Pereda Torres, Javier Eduardo; Díaz, M.; Gatica, Gabriel N.
    In this article, a linear control strategy is presented applied to a Synchronous Buck converter, which allows N sub-converters to operate in parallel, operating in Interleave mode, balancing the currents in each of the sub-converters and maintaining their dynamic response invariant over a wide range of operation, even when their DC links vary as it would be in a system with electric batteries. Simulation results validating this behavior, using variable DC sources are presented and discussed in this article.
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    MOONS: The New Multi-Object Spectrograph for the VLT
    (2020) Cirasuolo, M.; Fairley, A.; Rees, P.; González, O. A.; Taylor, W.; Maiolino, R.; Afonso, J.; Evans, C.; Flores, H.; Lilly, S.; Oliva, E.; Paltani, S.; Vanzi, L.; Abreu, M.; Accardo, M.; Adams, N.; Álvarez Méndez, D.; Amans, J. -P.; Amarantidis, S.; Atek, H.; Atkinson, D.; Banerji, M.; Barrett, J.; Barrientos, F.; Bauer, F.; Beard, S.; Béchet, C.; Belfiore, A.; Bellazzini, M.; Benoist, C.; Best, P.; Biazzo, K.; Black, M.; Boettger, D.; Bonifacio, P.; Bowler, R.; Bragaglia, A.; Brierley, S.; Brinchmann, J.; Brinkmann, M.; Buat, V.; Buitrago, F.; Burgarella, D.; Burningham, B.; Buscher, D.; Cabral, A.; Caffau, E.; Cardoso, L.; Carnall, A.; Carollo, M.; Castillo, R.; Castignani, G.; Catelan, Márcio; Cicone, C.; Cimatti, A.; Cioni, M. -R. L.; Clementini, G.; Cochrane, W.; Coelho, J.; Colling, M.; Contini, T.; Contreras, R.; Conzelmann, R.; Cresci, G.; Cropper, M.; Cucciati, O.; Cullen, F.; Cumani, C.; Curti, M.; Da Silva, A.; Daddi, E.; Dalessandro, E.; Dalessio, F.; Dauvin, L.; Davidson, G.; de Laverny, P.; Delplancke-Ströbele, F.; De Lucia, G.; Del Vecchio, C.; Dessauges-Zavadsky, M.; Di Matteo, P.; Dole, H.; Drass, H.; Dunlop, J.; Dünner, R.; Eales, S.; Ellis, R.; Enriques, B.; Fasola, G.; Ferguson, A.; Ferruzzi, D.; Fisher, M.; Flores, M.; Fontana, A.; Forchi, V.; Francois, P.; Franzetti, P.; Gargiulo, A.; Garilli, B.; Gaudemard, J.; Gieles, M.; Gilmore, G.; Ginolfi, M.; Gomes, J. M.; Guinouard, I.; Gutierrez, P.; Haigron, R.; Hammer, F.; Hammersley, P.; Haniff, C.; Harrison, C.; Haywood, M.; Hill, V.; Hubin, N.; Humphrey, A.; Ibata, R.; Infante, L.; Ives, D.; Ivison, R.; Iwert, O.; Jablonka, P.; Jakob, G.; Jarvis, M.; King, D.; Kneib, J. -P.; Laporte, P.; Lawrence, A.; Lee, D.; Li Causi, G.; Lorenzoni, S.; Lucatello, S.; Luco, Y.; Macleod, A.; Magliocchetti, M.; Magrini, L.; Mainieri, V.; Maire, C.; Mannucci, F.; Martin, N.; Matute, I.; Maurogordato, S.; McGee, S.; Mcleod, D.; McLure, R.; McMahon, R.; Melse, B. -T.; Messias, H.; Mucciarelli, A.; Nisini, B.; Nix, J.; Norberg, P.; Oesch, P.; Oliveira, A.; Origlia, L.; Padilla, N.; Palsa, R.; Pancino, E.; Papaderos, P.; Pappalardo, C.; Parry, I.; Pasquini, L.; Peacock, J.; Pedichini, F.; Pello, R.; Peng, Y.; Pentericci, L.; Pfuhl, O.; Piazzesi, R.; Popovic, D.; Pozzetti, L.; Puech, M.; Puzia, T.; Raichoor, A.; Randich, S.; Recio-Blanco, A.; Reis, S.; Reix, F.; Renzini, A.; Rodrigues, M.; Rojas, F.; Rojas-Arriagada, Á.; Rota, S.; Royer, F.; Sacco, G.; Sanchez-Janssen, R.; Sanna, N.; Santos, P.; Sarzi, M.; Schaerer, D.; Schiavon, R.; Schnell, R.; Schultheis, M.; Scodeggio, M.; Serjeant, S.; Shen, T. -C.; Simmonds, C.; Smoker, J.; Sobral, D.; Sordet, M.; Spérone, D.; Strachan, J.; Sun, X.; Swinbank, M.; Tait, G.; Tereno, I.; Tojeiro, R.; Torres, M.; Tosi, M.; Tozzi, A.; Tresiter, E.; Valenti, E.; Valenzuela Navarro, Á.; Vanzella, E.; Vergani, S.; Verhamme, A.; Vernet, J.; Vignali, C.; Vinther, J.; Von Dran, L.; Waring, C.; Watson, S.; Wild, V.; Willesme, B.; Woodward, B.; Wuyts, S.; Yang, Y.; Zamorani, G.; Zoccali, M.; Bluck, A.; Trussler, J.
    MOONS is the new Multi-Object Optical and Near-infrared Spectrograph currently under construction for the Very Large Telescope (VLT) at ESO. This remarkable instrument combines, for the first time, the collecting power of an 8-m telescope, 1000 fibres with individual robotic positioners, and both low- and high-resolution simultaneous spectral coverage across the 0.64-1.8 μm wavelength range. This facility will provide the astronomical community with a powerful, world-leading instrument able to serve a wide range of Galactic, extragalactic and cosmological studies. Construction is now proceeding full steam ahead and this overview article presents some of the science goals and the technical description of the MOONS instrument. More detailed information on the MOONS surveys is provided in the other dedicated articles in this Messenger issue....
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    Phase-shifted Pulse Width Modulation with alternate zeros voltage for parallel connection of H-Bridges for High-Current Low-Voltage applications
    (IEEE, 2019) Verdugo, D.; Rojas, F.; Lillo, J.; Diaz, M.; Pereda Torres, Javier Eduardo; Gatica, Gabriel N.
    Phase-Shifted Modulation (PSM) applied to multilevel converters is an effective method for reducing the output THD. In this paper, a new unipolar PSM method is proposed to control internal circulating current of a high-current low-voltage power converter, composed of parallel connected H- Bridges. The proposed method reduces the H-bridge currents distortions and the power losses of the overall converter. Simulation results comparing the standard unipolar modulation with the proposed unipolar modulation technique are performed to demonstrate its effectiveness.
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    Proper motions in the VVV Survey: Results for more than 15 million stars across NGC 6544
    (2017) Contreras Ramos, Rodrigo Andrés; Zoccali, Manuela; Rojas, F.; Rojas Arriagada, A.; Gárate, M.; Huijse, P.; Gran, F.; Valcarce Bravo, Aldo Alfonso Raúl; Estévez, P. A.; Minniti, D.
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    Reactive oxygen species trigger motoneuron death in non-cell-autonomous models of als through activation of c-Abl signaling
    (2015) Rojas, F.; Hernández Trejo, Diego Eduardo; Martínez Saavedra, Alexis; Álvarez Rojas, Alejandra
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    Solid State Transformers : Concepts, Classification, and Control
    (2020) Shamshuddin, M. A.; Rojas, F.; Cardenas, R.; Pereda Torres, Javier Eduardo; Diaz, M.; Kennel, R.
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    Status and evolution of the cryosphere in the Andes of Santiago (Chile, 33.5°S.)
    (2010) Bodin, X.; Rojas, F.; Brenning, A.
    In the context of a general retreat of glaciers in the dry Andes, this study focuses on the state and recent evolution of debris-covered glaciers and permafrost-related landforms, especially rock glaciers, in the semiarid to semihumid Laguna Negra catchment, a part of the Andes of central Chile at 33.5 degrees S, that is a key contributor of drinking water for the city of Santiago. We conducted catchment-scale geomorphological mapping, diachronic analysis of 1955 and 1996 orthophotographs and digital elevation models (DEMs), and the analysis of ground temperatures and their sensitivity to climate variation. Rock glaciers dominate spatially and in terms of water storage over glaciers (area ratio: 1.7:1; ratio of water equivalents: 1.5:1). An intense downwasting has affected both debris-covered and exposed glacier components in the Punta Negra subcatchment, a process that is associated with the growth of numerous thermokarst depressions. The altitudinal transect of ground temperature suggest that permafrost is widespread above similar to 4000 m asl, although it can also occur at lower elevations on sheltered footslopes and within rock glaciers. The sensitivity analysis indicates that the near-surface ground thermal regime at high altitudes is strongly influenced by the snow cover disappearance date, which may therefore constitute an important control on the effect of climatic warming. (C) 2010 Elsevier B.V. All rights reserved.
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    TOI-150b and TOI-163b : two transiting hot Jupiters, one eccentric and one inflated, revealed by TESS near and at the edge of the JWST CVZ
    (2019) Kossakowski, D.; Espinoza, N.; Brahm Scott, Rafael; Jordán Colzani, Andrés Cristóbal; Henning, T.; Rojas, F.; Kurster, M.; Sarkis, P.; Schlecker, M.; Pozuelos, F. J.; Barkaoui, K.; Jehin, E.; Gillon, M.; Matthews, E.; Horch, E. P.; Ciardi, D. R.; Rossfield, I. J. M.; Gonzales, E.; Howell, S. B.; Matson, R.; Schlieder, J.; Jenkins, J.; Ricker, G.; Seager, S.; Winn, J. N.; Li, J.; Rose, M. E.; Smith, J. C.; Dynes, S.; Morgan, E.; Villaseñor, J. N.; Charbonneau, D.; Jaffe, T.; Yu, L.; Bakos, G.; Bhatti, W.; Bouchy, F.; Collins, K. A.; Collins, K. I.; Csubry, Z.; Evans, P.; Jensen, E. L. N.; Lovis, C.; Marmier, M.; Nielsen, L. D.; Osip, D.; Pepe, F.; Relles, H. M.; Segransan, D.; Shporer, A.; Stockdale, C.; Suc, V.; Turner, O.; Udry, S.
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    TOI-677b : A Warm Jupiter (P=11.2 days) on an Eccentric Orbit Transiting a Late F-type Star
    (2020) Jordán Colzani, Andrés Cristóbal; Brahm Scott, Rafael; Espinoza, N.; Henning, T.; Jones Fernández, Matías Ignacio; Kossakowski, D.; Sarkis, P.; Trifonov, T.; Rojas, F.; Torres, P.; Drass, Holger; Nandakumar, S.; Barbieri, M.; Davis, A.; Wang, S. H.; Bayliss, D.; Bouma, L.; Dragomir, D.; Eastman, J. D.; Daylan, T.; Guerrero, N.; Barclay, T.; Ting, E. B.; Henze, C. E.; Ricker, G.; Vanderspek, R.; Latham, D. W.; Seager, S.; Winn, J.; Jenkins, J. M.; Wittenmyer, R. A.; Bowler, B. P.; Crossfield, I.; Horner, J.; Kane, S. R.; Kielkopf, J. F.; Morton, T. D.; Plavchan, P.; Tinney, C. G.; Addison, B.; Mengel, M. W.; Okumura, J.; Shahaf, S.; Mazeh, T.; Rabus, Markus; Shporer, A.; Ziegler, C.; Mann, A. W.; Hart, R.
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    Two long-period transiting exoplanets on eccentric orbits: NGTS-20 b (TOI-5152 b) and TOI-5153 b
    (2022) Ulmer-Moll, S.; Lendl, M.; Gill, S.; Villanueva, S.; Hobson, M. J.; Bouchy, F.; Brahm, R.; Dragomir, D.; Grieves, N.; Mordasini, C.; Anderson, D. R.; Acton, J. S.; Bayliss, D.; Bieryla, A.; Burleigh, M. R.; Casewell, S. L.; Chaverot, G.; Eigmueller, P.; Feliz, D.; Gaudi, B. S.; Gillen, E.; Goad, M. R.; Gupta, A. F.; Gunther, M. N.; Henderson, B. A.; Henning, T.; Jenkins, J. S.; Jones, M.; Jordan, A.; Kendall, A.; Latham, D. W.; Mireles, I; Moyano, M.; Nadol, J.; Osborn, H. P.; Pepper, J.; Pinto, M. T.; Psaridi, A.; Queloz, D.; Quinn, S.; Rojas, F.; Sarkis, P.; Schlecker, M.; Tilbrook, R. H.; Torres, P.; Trifonov, T.; Udry, S.; Vines, J., I; West, R.; Wheatley, P.; Yao, X.; Zhao, Y.; Zhou, G.
    Context. Long-period transiting planets provide the opportunity to better understand the formation and evolution of planetary systems. Their atmospheric properties remain largely unaltered by tidal or radiative effects of the host star, and their orbital arrangement reflects a different and less extreme migrational history compared to close-in objects. The sample of long-period exoplanets with well-determined masses and radii is still limited, but a growing number of long-period objects reveal themselves in the Transiting Exoplanet Survey Satellite (TESS) data.