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Author Escapil-Inchauspe, P.; Jerez-Hanckes, C.
Title Helmholtz Scattering by Random Domains: First-Order Sparse Boundary Elements Approximation Type Journal Article
Year 2020 Publication SIAM Journal of Scientific Computing Abbreviated Journal SIAM J. Sci. Comput.
Volume to appear Issue Pages
Keywords
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1064-8275 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number UAI @ eduardo.moreno @ Serial 1205
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Author Fernandez, M.; Munoz, F.D.; Moreno, R.
Title Analysis of imperfect competition in natural gas supply contracts for electric power generation: A closed-loop approach Type Journal Article
Year 2020 Publication Energy Economics Abbreviated Journal Energy Econ.
Volume 87 Issue Pages 15 pp
Keywords Market power; Natural gas; Electricity market; Generalized Nash equilibrium; Equilibrium Problem with Equilibrium; Constraints
Abstract The supply of natural gas is generally based on contracts that are signed prior to the use of this fuel for power generation. Scarcity of natural gas in systems where a share of electricity demand is supplied with gas turbines does not necessarily imply demand rationing, because most gas turbines can still operate with diesel when natural gas is not available. However, scarcity conditions can lead to electricity price spikes, with welfare effects for consumers and generation firms. We develop a closed-loop equilibrium model to evaluate if generation firms have incentives to contract or import the socially-optimal volumes of natural gas to generate electricity. We consider a perfectly-competitive electricity market, where all firms act as price-takers in the short term, but assume that only a small number of firms own gas turbines and procure natural gas from, for instance, foreign suppliers in liquefied form. We illustrate an application of our model using a network reduction of the electric power system in Chile, considering two strategic firms that make annual decisions about natural gas imports in discrete quantities. We also assume that strategic firms compete in the electricity market with a set of competitive firms do not make strategic decisions about natural gas imports (i.e., a competitive fringe). Our results indicate that strategic firms could have incentives to sign natural gas contracts for volumes that are much lower than the socially-optimal ones, which leads to supernormal profits for these firms in the electricity market. Yet, this effect is rather sensitive to the price of natural gas. A high price of natural gas eliminates the incentives of generation firms to exercise market power through natural gas contracts. (C) 2020 Elsevier B.V. All rights reserved.
Address [Fernandez, Mauricio; Munoz, Francisco D.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago, Chile, Email: fdmunoz@uai.cl
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0140-9883 ISBN Medium
Area Expedition Conference
Notes WOS:000536091600026 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1196
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Author Gill, S.; Wheatley, P.J.; Cooke, B.F.; Jordan, A.; Nielsen, L.D.; Bayliss, D.; Anderson, D.R.; Vines, J.I.; Lendl, M.; Acton, J.S.; Armstrong, D.J.; Bouchy, F.; Brahm, R.; Bryant, E.M.; Burleigh, M.R.; Casewell, S.L.; Eigmuller, P.; Espinoza, N.; Gillen, E.; Goad, M.R.; Grieves, N.; Gunther, M.N.; Henning, T.; Hobson, M.J.; Hogan, A.; Jenkins, J.S.; McCormac, J.; Moyano, M.; Osborn, H.P.; Pollacco, D.; Queloz, D.; Rauer, H.; Raynard, L.; Rojas, F.; Sarkis, P.; Smith, A.M.S.; Pinto, M.T.; Tilbrook, R.H.; Udry, S.; Watson, C.A.; West, R.G.
Title NGTS-11 b (TOI-1847 b): A Transiting Warm Saturn Recovered from a TESS Single-transit Event Type Journal Article
Year 2020 Publication Astrophysical Journal Letters Abbreviated Journal Astrophys. J. Lett.
Volume 898 Issue 1 Pages 6 pp
Keywords
Abstract We report the discovery of NGTS-11 b (=TOI-1847b), a transiting Saturn in a 35.46 day orbit around a mid K-type star (T-eff = 5050 +/- 80 K). We initially identified the system from a single-transit event in a TESS full-frame image light curve. Following 79 nights of photometric monitoring with an NGTS telescope, we observed a second full transit of NGTS-11 b approximately one year after the TESS single-transit event. The NGTS transit confirmed the parameters of the transit signal and restricted the orbital period to a set of 13 discrete periods. We combined our transit detections with precise radial-velocity measurements to determine the true orbital period and measure the mass of the planet. We find NGTS-11 b has a radius of 0.817 +/-(0.028)(0.032) R-Jup, a mass of 0.344 +/-(0.092)(0.073) M-Jup, and an equilibrium temperature of just 435 +/-(34)(32) K, making it one of the coolest known transiting gas giants. NGTS-11 b is the first exoplanet to be discovered after being initially identified as a TESS single-transit event, and its discovery highlights the power of intense photometric monitoring in recovering longer-period transiting exoplanets from single-transit events.
Address [Gill, Samuel; Wheatley, Peter J.; Armstrong, David J.; Bryant, Edward M.; Pollacco, Don] Univ Warwick, Ctr Exoplanets & Habitabil, Gibbet Hill Rd, Coventry CV4 7AL, W Midlands, England, Email: samuel.gill@warwick.ac.uk
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-8205 ISBN Medium
Area Expedition Conference
Notes WOS:000553513300001 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1213
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Author Goles, E.; Montealegre, P.; Rios-Wilson, M.
Title On The Effects Of Firing Memory In The Dynamics Of Conjunctive Networks Type Journal Article
Year 2020 Publication Discrete And Continuous Dynamical Systems Abbreviated Journal Discret. Contin. Dyn. Syst.
Volume 40 Issue 10 Pages 5765-5793
Keywords Discrete dynamical systems; boolean network; firing memory; conjunctive networks; prediction problem; and PSPACE
Abstract A boolean network is a map F : {0, 1}(n) -> {0, 1}(n) that defines a discrete dynamical system by the subsequent iterations of F. Nevertheless, it is thought that this definition is not always reliable in the context of applications, especially in biology. Concerning this issue, models based in the concept of adding asynchronicity to the dynamics were propose. Particularly, we are interested in a approach based in the concept of delay. We focus in a specific type of delay called firing memory and it effects in the dynamics of symmetric (non-directed) conjunctive networks. We find, in the caseis in which the implementation of the delay is not uniform, that all the complexity of the dynamics is somehow encapsulated in the component in which the delay has effect. Thus, we show, in the homogeneous case, that it is possible to exhibit attractors of non-polynomial period. In addition, we study the prediction problem consisting in, given an initial condition, determinate if a fixed coordinate will eventually change its state. We find again that in the non-homogeneous case all the complexity is determined by the component that is affected by the delay and we conclude in the homogeneous case that this problem is PSPACE-complete.
Address [Goles, Eric; Montealegre, Pedro] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Diagonal Torres 2650, Santiago, Chile, Email: eric.chacc@uai.cl;
Corporate Author Thesis
Publisher Amer Inst Mathematical Sciences-Aims Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1078-0947 ISBN Medium
Area Expedition Conference
Notes WOS:000545661800006 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1183
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Author Goles, E.; Tsompanas, M.A.; Adamatzky, A.; Tegelaar, M.; Wosten, H.A.B.; Martinez, G.J.
Title Computational universality of fungal sandpile automata Type Journal Article
Year 2020 Publication Physics Letters A Abbreviated Journal Phys. Lett. A
Volume 384 Issue 22 Pages 8 pp
Keywords Fungi; Sandpile automata; Computational universality
Abstract Hyphae within the mycelia of the ascomycetous fungi are compartmentalised by septa. Each septum has a pore that allows for inter-compartmental and inter-hyphal streaming of cytosol and even organelles. The compartments, however, have special organelles, Woronin bodies, that can plug the pores. When the pores are blocked, no flow of cytoplasm takes place. Inspired by the controllable compartmentalisation within the mycelium of the ascomycetous fungi we designed two-dimensional fungal automata. A fungal automaton is a cellular automaton where communication between neighbouring cells can be blocked on demand. We demonstrate computational universality of the fungal automata by implementing sandpile cellular automata circuits there. We reduce the Monotone Circuit Value Problem to the Fungal Automaton Prediction Problem. We construct families of wires, cross-overs and gates to prove that the fungal automata are P-complete. (C) 2020 Elsevier B.V. All rights reserved.
Address [Goles, Eric; Tsompanas, Michail-Antisthenis; Adamatzky, Andrew; Martinez, Genaro J.] Univ West England, Unconvent Comp Lab, Bristol, Avon, England, Email: andrew.adamatzky@uwe.ac.uk
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0375-9601 ISBN Medium
Area Expedition Conference
Notes WOS:000537033500017 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1194
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Author Golovach, P.A.; Heggernes, P.; Lima, P.T.; Montealegre, P.
Title Finding connected secluded subgraphs Type Journal Article
Year 2020 Publication Journal Of Computer And System Sciences Abbreviated Journal J. Comput. Syst. Sci.
Volume 113 Issue Pages 101-124
Keywords Secluded subgraph; Parameterized complexity; Forbidden subgraphs
Abstract Problems related to finding induced subgraphs satisfying given properties form one of the most studied areas within graph algorithms. However, for many applications, it is desirable that the found subgraph has as few connections to the rest of the graph as possible, which gives rise to the SECLUDED Pi-SUBGRAPH problem. Here, input k is the size of the desired subgraph, and input t is a limit on the number of neighbors this subgraph has in the rest of the graph. This problem has been studied from a parameterized perspective, and unfortunately it turns out to be W[1]-hard for many graph properties Pi, even when parameterized by k + t. We show that the situation changes when we are looking for a connected induced subgraph satisfying Pi. In particular, we show that the CONNECTED SECLUDED Pi-SUBGRAPH problem is FPT when parameterized by just t for many important graph properties Pi. (C) 2020 Elsevier Inc. All rights reserved.
Address [Golovach, Petr A.; Heggernes, Pinar; Lima, Paloma T.] Univ Bergen, Dept Informat, N-5020 Bergen, Norway, Email: petr.golovach@uib.no;
Corporate Author Thesis
Publisher Academic Press Inc Elsevier Science Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-0000 ISBN Medium
Area Expedition Conference
Notes WOS:000539435200006 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1191
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Author Gonzalez, E.; Villena, M.J.
Title On the spatial dynamics of vaccination: A spatial SIRS-V model Type Journal Article
Year 2020 Publication Computers & Mathematics With Applications Abbreviated Journal Comput. Math. Appl.
Volume 80 Issue 5 Pages 733-743
Keywords Epidemic dynamics; Spatial SIR model; Vaccination strategy; Non-linear system of partial differential equations; Numerical modeling
Abstract In this paper, we analyze the effects of vaccination from a spatial perspective. We propose a spatial deterministic SIRS-V model, which considers a non-linear system of partial differential equations with explicit attrition and diffusion terms for the vaccination process. The model allows us to simulate numerically the spatial and temporal dynamics of an epidemic, considering different spatial strategies for the vaccination policy. In particular, in our first example we analyze the classical SIRS-V evolution with the addition of movements due to diffusion, while in the second one we focus on modeling one ring vaccination policy. We expect this model can improve spatial predictions of SIR vaccination models by taking into account the spatial dimension of the problem. (C) 2020 Elsevier Ltd. All rights reserved.
Address [Gonzalez, Eduardo] Univ Finis Terrae, Fac Engn, Santiago, Chile, Email: e.gonzalez@ieee.org;
Corporate Author Thesis
Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0898-1221 ISBN Medium
Area Expedition Conference
Notes WOS:000557765800010 Approved no
Call Number UAI @ alexi.delcanto @ Serial 1220
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Author Guevara, E.; Babonneau, F.; Homem-de-Mello, T.; Moret, S.
Title A machine learning and distributionally robust optimization framework for strategic energy planning under uncertainty Type Journal Article
Year 2020 Publication Applied Energy Abbreviated Journal Appl. Energy
Volume 271 Issue Pages 18 pp
Keywords Strategic energy planning; Electricity generation; Uncertainty; Distributionally robust optimization; Machine learning
Abstract This paper investigates how the choice of stochastic approaches and distribution assumptions impacts strategic investment decisions in energy planning problems. We formulate a two-stage stochastic programming model assuming different distributions for the input parameters and show that there is significant discrepancy among the associated stochastic solutions and other robust solutions published in the literature. To remedy this sensitivity issue, we propose a combined machine learning and distributionally robust optimization (DRO) approach which produces more robust and stable strategic investment decisions with respect to uncertainty assumptions. DRO is applied to deal with ambiguous probability distributions and Machine Learning is used to restrict the DRO model to a subset of important uncertain parameters ensuring computational tractability. Finally, we perform an out-of-sample simulation process to evaluate solutions performances. The Swiss energy system is used as a case study all along the paper to validate the approach.
Address [Guevara, Esnil] Univ Adolfo Ibanez, PhD Program Ind Engn & Operat Res, Santiago, Chile, Email: frederic.babonneau@uai.cl
Corporate Author Thesis
Publisher Elsevier Sci Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0306-2619 ISBN Medium
Area Expedition Conference
Notes WOS:000540436500003 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1188
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Author Hojman, S.A.; Asenjo, F.A.
Title Classical and Quantum Dispersion Relations Type Journal Article
Year 2020 Publication Physica Scripta Abbreviated Journal Phys. Scr.
Volume 95 Issue 8 Pages 7 pp
Keywords Quantum Hamilton-Jacobi equation; Bohm potential; dispersion relation
Abstract It is showed that, in general, classical and quantum dispersion relations are different due to the presence of the Bohm potential. There are exact particular solutions of the quantum (wave) theory which obey the classical dispersion relation, but they differ in the general case. The dispersion relations may also coincide when additional assumptions are made, such as WKB or eikonal approximations, for instance. This general result also holds for non-quantum wave equations derived from classical counterparts, such as in ray and wave optics, for instance. Explicit examples are given for covariant scalar, vectorial and tensorial fields in flat and curved spacetimes.
Address [Hojman, Sergio A.] Univ Adolfo Ibanez, Fac Artes Liberales, Dept Ciencias, Santiago 7491169, Chile, Email: sergio.hojman@uai.cl;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-8949 ISBN Medium
Area Expedition Conference
Notes WOS:000543208700001 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1184
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Author Josserand, C.; Pomeau, Y.; Rica, S.
Title Finite-time localized singularities as a mechanism for turbulent dissipation Type Journal Article
Year 2020 Publication Physical Review Fluids Abbreviated Journal Phys. Rev. Fluids
Volume 5 Issue 5 Pages 15 pp
Keywords
Abstract The nature of the fluctuations of the dissipation rate in fluid turbulence is still under debate. One reason may be that the observed fluctuations are strong events of dissipation, which reveal the trace of spatiotemporal singularities of the Euler equations, which are the zero viscosity limit of ordinary incompressible fluids. Viscosity regularizes these hypothetical singularities, resulting in a chaotic fluctuating state in which the strong events appear randomly in space and time, making the energy dissipation highly fluctuating. Yet, to date, it is not known if smooth initial conditions of the Euler equations with finite energy do or do not blow up in finite time. We overcome this central difficulty by providing a scenario for singularity-mediated turbulence based on the self-focusing nonlinear Schrodinger equation. It avoids the intrinsic difficulty of Euler equations since it is well known that solutions of this NLS equation with smooth initial conditions do blow up in finite time. When adding viscosity, the model shows (i) that dissipation takes place near the singularities only, (ii) that such intense events are random in space and time, (iii) that the mean dissipation rate is almost constant as the viscosity varies, and (iv) the observation of an Obukhov-Kolmogorov spectrum with a power-law dependence together with an intermittent behavior using structure function correlations, in close correspondence with the one measured in fluid turbulence.
Address [Josserand, Christophe; Pomeau, Yves; Rica, Sergio] CNRS, LadHyX, F-91128 Palaiseau, France, Email: sergio.rica@uai.cl
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-990x ISBN Medium
Area Expedition Conference
Notes WOS:000535862800004 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1198
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Author Kamal, C.; Gravelle, S.; Botto, L.
Title Hydrodynamic slip can align thin nanoplatelets in shear flow Type Journal Article
Year 2020 Publication Nature Communications Abbreviated Journal Nat. Commun.
Volume 11 Issue 1 Pages 10 pp
Keywords
Abstract The large-scale processing of nanomaterials such as graphene and MoS2 relies on understanding the flow behaviour of nanometrically-thin platelets suspended in liquids. Here we show, by combining non-equilibrium molecular dynamics and continuum simulations, that rigid nanoplatelets can attain a stable orientation for sufficiently strong flows. Such a stable orientation is in contradiction with the rotational motion predicted by classical colloidal hydrodynamics. This surprising effect is due to hydrodynamic slip at the liquid-solid interface and occurs when the slip length is larger than the platelet thickness; a slip length of a few nanometers may be sufficient to observe alignment. The predictions we developed by examining pure and surface-modified graphene is applicable to different solvent/2D material combinations. The emergence of a fixed orientation in a direction nearly parallel to the flow implies a slip-dependent change in several macroscopic transport properties, with potential impact on applications ranging from functional inks to nanocomposites. Current theories predict that a plate-like particle rotates continuously in a shear flow. Kamal et al. instead show that even nanometric hydrodynamic slip may induce a thin plate-like particle to adopt a stable orientation, and discuss implications of this effect for flow processing of 2D nanomaterials.
Address [Kamal, Catherine; Gravelle, Simon; Botto, Lorenzo] Queen Mary Univ London, Sch Engn & Mat Sci, London, England, Email: l.botto@tudelft.nl
Corporate Author Thesis
Publisher Nature Publishing Group Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Medium
Area Expedition Conference
Notes WOS:000536569900023 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1195
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Author Lagos, F.; Schreiber, M.R.; Parsons, S.G.; Zurlo, A.; Mesa, D.; Gansicke, B.T.; Brahm, R.; Caceres, C.; Canovas, H.; Hernandez, M.S.; Jordan, A.; Koester, D.; Schmidtobreick, L.; Tappert, C.; Zorotovic, M.
Title The White Dwarf Binary Pathways Survey -III. Contamination from hierarchical triples containing a white dwarf Type Journal Article
Year 2020 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 494 Issue 1 Pages 915-922
Keywords methods: numerical; methods: statistical; binaries: close; stars: kinematics and dynamics
Abstract The White Dwarf Binary Pathways Survey aims at increasing the number of known detached A, F, G, and K main-sequence stars in close orbits with white dwarf companions (WD+AFGK binaries) to refine our understanding about compact binary evolution and the nature of Supernova Ia progenitors. These close WD+AFGK binary stars are expected to form through common envelope evolution, in which tidal forces tend to circularize the orbit. However, some of the identified WD+AFGK binary candidates show eccentric orbits, indicating that these systems are either formed through a different mechanism or perhaps they are not close WD+AFGK binaries. We observed one of these eccentric WD+AFGK binaries with SPHERE and find that the system TYC 7218-934-1 is in fact a triple system where the WD is a distant companion. The inner binary likely consists of the G-type star plus an unseen low-mass companion in an eccentric orbit. Based on this finding, we estimate the fraction of triple systems that could contaminate the WD+AFGK sample. We find that less than 15 per cent of our targets with orbital periods shorter than 100 d might be hierarchical triples.
Address [Lagos, F.; Schreiber, M. R.; Hernandez, M-S; Tappert, C.; Zorotovic, M.] Univ Valparaiso, Inst Fis & Astron, Valparaiso, Chile, Email: felipe.lagos@pmigrado.uv.cl;
Corporate Author Thesis
Publisher Oxford Univ Press Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000535885900070 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1197
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Author Montealegre, R.; Perez-Salazar, S.; Rapaport, I.; Todinca, I.
Title Graph reconstruction in the congested clique Type Journal Article
Year 2020 Publication Journal Of Computer And System Sciences Abbreviated Journal J. Comput. Syst. Sci.
Volume 113 Issue Pages 1-17
Keywords Distributed computing; Congested clique; Round complexity; Reconstruction problem; Graph classes
Abstract In this paper we study the reconstruction problem in the congested clique model. Given a class of graphs g, the problem is defined as follows: if G is not an element of g, then every node must reject; if G is an element of g, then every node must end up knowing all the edges of G. The cost of an algorithm is the total number of bits received by any node through one link. It is not difficult to see that the cost of any algorithm that solves this problem is Omega(log vertical bar g(n)vertical bar/n), where g(n) is the subclass of all n-node labeled graphs in g. We prove that the lower bound is tight and that it is possible to achieve it with only 2 rounds. (C) 2020 Elsevier Inc. All rights reserved.
Address [Montealegre, R.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago, Chile, Email: p.montealegre@edu.uai;
Corporate Author Thesis
Publisher Academic Press Inc Elsevier Science Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-0000 ISBN Medium
Area Expedition Conference
Notes WOS:000539435200001 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1190
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Author Munoz, M.; Robles-Navarro, A.; Fuentealba, P.; Cardenas, C.
Title Predicting Deprotonation Sites Using Alchemical Derivatives Type Journal Article
Year 2020 Publication Journal Of Physical Chemistry A Abbreviated Journal J. Phys. Chem. A
Volume 124 Issue 19 Pages 3754-3760
Keywords
Abstract An alchemical transformation is any process, physical or fictitious, that connects two points in the chemical space. A particularly important transformation is the vanishing of a proton, whose energy can be linked to the proton dissociation enthalpy of acids. In this work we assess the reliability of alchemical derivatives in predicting the proton dissociation enthalpy of a diverse series of mono- and polyprotic molecules. Alchemical derivatives perform remarkably well in ranking the proton affinity of all molecules. Additionally, alchemical derivatives could be use also as a predictive tool because their predictions correlate quite well with calculations based on energy differences and experimental values. Although second-order alchemical derivatives underestimate the dissociation enthalpy, the deviation seems to be almost constant. This makes alchemical derivatives extremely accurate to evaluate the difference in proton affinity between two acid sites of polyprotic molecule. Finally, we show that the reason for the underestimation of the dissociation enthalpy is most likely the contribution of higher-order derivatives.
Address [Robles-Navarro, Andres; Fuentealba, Patricio; Cardenas, Carlos] Univ Chile, Fac Ciencias, Dept Fis, Casilla 653, Santiago, Chile, Email: pfuentea@uchile.cl;
Corporate Author Thesis
Publisher Amer Chemical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1089-5639 ISBN Medium
Area Expedition Conference
Notes WOS:000535280400008 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1199
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Author Nielsen, L.D.; Brahm, R.; Bouchy, F.; Espinoza, N.; Turner, O.; Rappaport, S.; Pearce, L.; Ricker, G.; Vanderspek, R.; Latham, D.W.; Seager, S.; Winn, J.N.; Jenkins, J.M.; Acton, J.S.; Bakos, G.; Barclay, T.; Barkaoui, K.; Bhatti, W.; Briceno, C.; Bryant, E.M.; Burleigh, M.R.; Ciardi, D.R.; Collins, K.A.; Collins, K.I.; Cooke, B.F.; Csubry, Z.; dos Santos, L.A.; Eigmuller, P.; Fausnaugh, M.M.; Gan, T.; Gillon, M.; Goad, M.R.; Guerrero, N.; Hagelberg, J.; Hart, R.; Henning, T.; Huang, C.X.; Jehin, E.; Jenkins, J.S.; Jordan, A.; Kielkopf, J.F.; Kossakowski, D.; Lavie, B.; Law, N.; Lendl, M.; de Leon, J.P.; Lovis, C.; Mann, A.W.; Marmier, M.; McCormac, J.; Mori, M.; Moyano, M.; Narita, N.; Osip, D.; Otegi, J.F.; Pepe, F.; Pozuelos, F.J.; Raynard, L.; Relles, H.M.; Sarkis, P.; Segransan, D.; Seidel, J.V.; Shporer, A.; Stalport, M.; Stockdale, C.; Suc, V.; Tamura, M.; Tan, T.G.; Tilbrook, R.H.; Ting, E.B.; Trifonov, T.; Udry, S.; Vanderburg, A.; Wheatley, P.J.; Wingham, G.; Zhan, Z.; Ziegler, C.
Title Three short-period Jupiters from TESS: HIP 65Ab, TOI-157b, and TOI-169b Type Journal Article
Year 2020 Publication Astronomy & Astrophysics Abbreviated Journal Astron. Astrophys.
Volume 639 Issue Pages 17 pp
Keywords planets and satellites: detection; planets and satellites: individual: TOI-129; planets and satellites: individual: HIP 65A; planets and satellites: individual: TOI-157
Abstract We report the confirmation and mass determination of three hot Jupiters discovered by the Transiting Exoplanet Survey Satellite (TESS) mission: HIP 65Ab (TOI-129, TIC-201248411) is an ultra-short-period Jupiter orbiting a bright (V = 11.1 mag) K4-dwarf every 0.98 days. It is a massive 3.213 +/- 0.078 M-J planet in a grazing transit configuration with an impact parameter of b = 1.17(-0.08)(+0.10) b=1.17-0.08+0.10 . As a result the radius is poorly constrained, 2.03(-0.49)(+0.61)R(J) 2.03-0.49+0.61 RJ . The planet's distance to its host star is less than twice the separation at which it would be destroyed by Roche lobe overflow. It is expected to spiral into HIP 65A on a timescale ranging from 80 Myr to a few gigayears, assuming a reduced tidal dissipation quality factor of Q(s)(') = 10(7) – 10(9) Qs ' =107-109 . We performed a full phase-curve analysis of the TESS data and detected both illumination- and ellipsoidal variations as well as Doppler boosting. HIP 65A is part of a binary stellar system, with HIP 65B separated by 269 AU (3.95 arcsec on sky). TOI-157b (TIC 140691463) is a typical hot Jupiter with a mass of 1.18 +/- 0.13 M-J and a radius of 1.29 +/- 0.02 R-J. It has a period of 2.08 days, which corresponds to a separation of just 0.03 AU. This makes TOI-157 an interesting system, as the host star is an evolved G9 sub-giant star (V = 12.7). TOI-169b (TIC 183120439) is a bloated Jupiter orbiting a V = 12.4 G-type star. It has a mass of 0.79 +/- 0.06 M-J and a radius of 1.09(-0.05)(+0.08)R(J) 1.09-0.05+0.08<mml:msub>RJ . Despite having the longest orbital period (P = 2.26 days) of the three planets, TOI-169b receives the most irradiation and is situated on the edge of the Neptune desert. All three host stars are metal rich with [Fe / H] ranging from 0.18 to0.24.
Address [Nielsen, L. D.; Bouchy, F.; Turner, O.; dos Santos, L. A.; Hagelberg, J.; Lavie, B.; Lendl, M.; Lovis, C.; Marmier, M.; Otegi, J. F.; Pepe, F.; Segransan, D.; Seidel, J., V; Stalport, M.; Udry, S.] Univ Geneva, Geneva Observ, Chemin Mailettes 51, CH-1290 Versoix, Switzerland, Email: louise.nielsen@unige.ch
Corporate Author Thesis
Publisher Edp Sciences S A Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6361 ISBN Medium
Area Expedition Conference
Notes WOS:000554478300001 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1215
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Author Pabon-Pereira, C.P.; Hamelers, H.V.M.; Matilla, I.; van Lier, J.B.
Title New Insights on the Estimation of the Anaerobic Biodegradability of Plant Material: Identifying Valuable Plants for Sustainable Energy Production Type Journal Article
Year 2020 Publication Processes Abbreviated Journal Processes
Volume 8 Issue 7 Pages 23 pp
Keywords anaerobic digestion; biodegradability; lignocellulosics; fiber degradation
Abstract Based on fifteen European plant species, a statistical model for the estimation of the anaerobic biodegradability of plant material was developed. We show that this new approach represents an accurate and cost-effective method to identify valuable energy plants for sustainable energy production. In particular, anaerobic biodegradability (B-o) of lignocellulosic material was empirically found to be related to the amount of cellulose plus lignin, as analytically assessed by the van Soest method, i.e., the acid detergent fiber (ADF) value. Apart from being theoretically meaningful, the ADF-based empirical model requires the least effort compared to the other four proposed conceptual models proposed, as individual fractions of cellulose, hemicellulose, and lignin do not need to be assessed, which also enhances the predictive accuracy of the model's estimation. The model's results showed great predictability power, allowing us to identify interesting crops for sustainable crop rotations. Finally, the model was used to predictB(o)of 114 European plant samples that had been previously characterized by means of the van Soest method.
Address [Pabon-Pereira, Claudia P.] Univ Adolfo Ibanez, Fac Engn & Sci, Diagonal Las Torres 2700, Penalolen 2700, Santiago De Chi, Chile, Email: claudia.pabon@uai.cl;
Corporate Author Thesis
Publisher Mdpi Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes WOS:000556716400001 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1217
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Author Reus, L.; Fabozzi, F.J.
Title Robust Solutions to the Life-Cycle Consumption Problem Type Journal Article
Year Publication Computational Economics Abbreviated Journal Comput. Econ.
Volume Issue Pages 19 pp
Keywords Life-cycle consumption problem; Intertemporal portfolio-choice problem; Robust optimization; Robust counterpart framework
Abstract This paper demonstrates how the well-known discrete life-cycle consumption problem (LCP) can be solved using the Robust Counterpart (RC) formulation technique, as defined in Ben-Tal and Nemirovski (Math Oper Res 23(4):769-805, 1998). To do this, we propose a methodology that involves applying a change of variables over the original consumption before deriving the RC. These transformations allow deriving a closed solution to the inner problem, and thus to solve the LCP without facing the curse of dimensionality and without needing to specify the prior distribution for the investment opportunity set. We generalize the methodology and illustrate how it can be used to solve other type of problems. The results show that our methodology enables solving long-term instances of the LCP (30 years). We also show it provides an alternative consumption pattern as to the one provided by a benchmark that uses a dynamic programming approach. Rather than finding a consumption that maximizes the expected lifetime utility, our solution delivers higher utilities for worst-case scenarios of future returns.
Address [Reus, Lorenzo] Univ Adolfo Ibanez, Engn & Sci, Diagonal Torres 2640, Santiago, Chile, Email: lorenzo.reus@uai.cl;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0927-7099 ISBN Medium
Area Expedition Conference
Notes WOS:000560958000001 Approved yes
Call Number UAI @ alexi.delcanto @ Serial 1222
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Author Reus, L.; Carrasco, J.A.; Pincheira, P.
Title Do it with a smile: Forecasting volatility with currency options Type Journal Article
Year 2020 Publication Finance Research Letters Abbreviated Journal Financ. Res. Lett.
Volume 34 Issue Pages 10 pp
Keywords Volatility forecast; Volatility smile; Latin American markets; Currency options
Abstract We show that traditional measures of curvature and symmetry of the “smiles” improve volatility predictions in forex markets. We consider post crisis data at a daily basis for seven currencies vis a vis the American dollar: The British pound, the Euro, the Australian dollar, the Japanese yen, the Brazilian real and the Mexican and Chilean peso. While our results are robust to the option currency and maturity, they are particularly strong for latin-American currencies and options with longer maturity. We find that the simultaneous inclusion of skewness and kurtosis to a forecasting model significantly improves its predictive accuracy.
Address [Reus, Lorenzo; Carrasco, Jose A.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago 2640, Chile, Email: lorenzo.reus@uai.cl;
Corporate Author Thesis
Publisher Academic Press Inc Elsevier Science Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1544-6123 ISBN Medium
Area Expedition Conference
Notes WOS:000551346400022 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1209
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Author Ritt, M.; Pereira, J.
Title Heuristic and exact algorithms for minimum-weight non-spanning arborescences Type Journal Article
Year 2020 Publication European Journal Of Operational Research Abbreviated Journal Eur. J. Oper. Res.
Volume 287 Issue 1 Pages 61-75
Keywords Minimum-weight non-spanning arborescence; Heuristic; Iterated Local Search; Branch-and-cut
Abstract We address the problem of finding an arborescence of minimum total edge weight rooted at a given vertex in a directed, edge-weighted graph. If the arborescence must span all vertices the problem is solvable in polynomial time, but the non-spanning version is NP-hard. We propose reduction rules which determine vertices that are required or can be excluded from optimal solutions, a modification of Edmonds algorithm to construct arborescences that span a given set of selected vertices, and embed this procedure into an iterated local search for good vertex selections. Moreover, we propose a cutset-based integer linear programming formulation, provide different linear relaxations to reduce the number of variables in the model and solve the reduced model using a branch-and-cut approach. We give extensive computational results showing that both the heuristic and the exact methods are effective and obtain better solutions on instances from the literature than existing approaches, often in much less time. (C) 2020 Elsevier B.V. All rights reserved.
Address [Ritt, Marcus] Univ Fed Rio Grande do Sul, Inst Informat, Av Bento Goncalves 9500, Porto Alegre, RS, Brazil, Email: marcus.ritt@inf.ufrgs.br;
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0377-2217 ISBN Medium
Area Expedition Conference
Notes WOS:000541072800005 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1187
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Author Sanchez, R.; Villena, M.
Title Comparative evaluation of wearable devices for measuring elevation gain in mountain physical activities Type Journal Article
Year 2020 Publication Proceedings Of The Institution Of Mechanical Engineers Part P-Journal Of Sports Engineering And Technology Abbreviated Journal Proc. Inst. Mech. Eng. Part P-J. Sport. Eng. Technol.
Volume to appear Issue Pages 8 pp
Keywords Mountain running; physical workload; altitude; measuring; validity; GPS; barometric device
Abstract The aim of this article is to examine the validity of elevation gain measures in mountain activities, such as hiking and mountain running, using different wearable devices and post-processing procedures. In particular, a total of 202 efforts were recorded and evaluated using three standard devices: GPS watch, GPS watch with barometric altimeter, and smartphone. A benchmark was based on orthorectified aerial photogrammetric survey conducted by the Chilean Air Force. All devices presented considerable elevation gain measuring errors, where the barometric device consistently overestimated elevation gain, while the GPS devices consistently underestimated elevation gain. The incorporation of secondary information in the post-processing can substantially improve the elevation gain measuring accuracy independently of the device and altitude measuring technology, reducing the error from -5% to -1%. These results could help coaches and athletes correct elevation gain estimations using the proposed technique, which would serve as better estimates of physical workload in mountain physical activities.
Address [Sanchez, Raimundo; Villena, Marcelo] Adolfo Ibanez Univ, Fac Engn & Sci, Diagonal Las Torres 2640, Santiago 7910000, Chile, Email: raimundo.sanchez@uai.cl
Corporate Author Thesis
Publisher Sage Publications Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1754-3371 ISBN Medium
Area Expedition Conference
Notes WOS:000534320000001 Approved no
Call Number UAI @ eduardo.moreno @ Serial 1201
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